From 0d1fc73fbd37abe54318a0c66b496067de3cd7ad Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 12:40:42 +0200
Subject: [PATCH 01/17] refactor: satisfy strict nightly lints without broad
 allows

---
 gateway/src/gateway.rs       | 124 +++++++++-------
 live-search/src/app.rs       | 267 ++++++++++++++++++++---------------
 live-search/src/bootstrap.rs |  49 ++++---
 3 files changed, 262 insertions(+), 178 deletions(-)

diff --git a/gateway/src/gateway.rs b/gateway/src/gateway.rs
index 19bf215..a61389d 100644
--- a/gateway/src/gateway.rs
+++ b/gateway/src/gateway.rs
@@ -86,20 +86,52 @@ pub fn build_gateway(modules: Vec<Arc<dyn ServiceModule>>) -> Result<Router, any
     )
 }
 
-/// Compose every `ServiceModule` with pre-loaded settings and runtime state.
-///
-/// # Errors
-/// Returns an error if TTLs are invalid, the HTTP client cannot be built, or
-/// rate-limiter configuration fails.
-#[instrument(skip(modules, settings, db_pool))]
-pub fn build_gateway_with_settings(
+fn service_infos(modules: &[Arc<dyn ServiceModule>]) -> Vec<ServiceInfo> {
+    modules
+        .iter()
+        .map(|module| ServiceInfo {
+            name: module.name(),
+            path: module.path(),
+            description: module.description(),
+            enabled: module.enabled(),
+        })
+        .collect()
+}
+
+fn enabled_service_router(modules: &[Arc<dyn ServiceModule>]) -> Router<GatewayState> {
+    modules
+        .iter()
+        .filter(|module| module.enabled())
+        .fold(Router::new(), |router, module| {
+            router.nest(&format!("/{}", module.path()), module.router())
+        })
+}
+
+async fn csrf_token_handler(
+    session: tower_sessions::Session,
+) -> Result<Json<serde_json::Value>, crate::auth::error::AppError> {
+    let token = crate::csrf::get_or_create_token(&session)
+        .await
+        .map_err(|error| {
+            crate::auth::error::AppError::internal(
+                "csrf token bootstrap",
+                std::io::Error::other(error),
+            )
+        })?;
+    Ok(Json(serde_json::json!({
+        "csrf_token": token.as_str(),
+        "header": crate::csrf::TOKEN_HEADER,
+    })))
+}
+
+fn gateway_state(
     modules: Vec<Arc<dyn ServiceModule>>,
     mut settings: settings::Settings,
     proxy_upstream_url: String,
     db_pool: Option<sqlx::PgPool>,
     refresh_token_ttl_secs: i64,
     access_token_ttl_secs: i64,
-) -> Result<Router, anyhow::Error> {
+) -> Result<(GatewayState, Router<GatewayState>), anyhow::Error> {
     if refresh_token_ttl_secs <= 0 || access_token_ttl_secs <= 0 {
         anyhow::bail!("gateway token TTLs must be positive");
     }
@@ -109,40 +141,51 @@ pub fn build_gateway_with_settings(
     settings.access_token_ttl_secs = access_token_ttl_secs;
 
     let (tx, _rx) = broadcast::channel(settings.sse_broadcast_buffer);
-
-    let service_infos: Vec<ServiceInfo> = modules
-        .iter()
-        .map(|module| ServiceInfo {
-            name: module.name(),
-            path: module.path(),
-            description: module.description(),
-            enabled: module.enabled(),
-        })
-        .collect();
-
-    let mut service_router: Router<GatewayState> = Router::new();
-    for module in &modules {
-        if module.enabled() {
-            service_router = service_router.nest(&format!("/{}", module.path()), module.router());
-        }
-    }
-
+    let services = service_infos(&modules);
+    let service_router = enabled_service_router(&modules);
     let http_client = reqwest::Client::builder()
         .timeout(Duration::from_secs(5))
         .build()
         .context("failed to build reqwest client")?;
 
-    let state = GatewayState {
-        tx,
-        services: service_infos,
+    Ok((
+        GatewayState {
+            tx,
+            services,
+            modules,
+            settings,
+            proxy_upstream_url: proxy_upstream_url.into(),
+            db_pool,
+            refresh_token_ttl_secs,
+            access_token_ttl_secs,
+            http_client,
+        },
+        service_router,
+    ))
+}
+
+/// Compose every `ServiceModule` with pre-loaded settings and runtime state.
+///
+/// # Errors
+/// Returns an error if TTLs are invalid, the HTTP client cannot be built, or
+/// rate-limiter configuration fails.
+#[instrument(skip(modules, settings, db_pool))]
+pub fn build_gateway_with_settings(
+    modules: Vec<Arc<dyn ServiceModule>>,
+    mut settings: settings::Settings,
+    proxy_upstream_url: String,
+    db_pool: Option<sqlx::PgPool>,
+    refresh_token_ttl_secs: i64,
+    access_token_ttl_secs: i64,
+) -> Result<Router, anyhow::Error> {
+    let (state, service_router) = gateway_state(
         modules,
         settings,
-        proxy_upstream_url: proxy_upstream_url.into(),
+        proxy_upstream_url,
         db_pool,
         refresh_token_ttl_secs,
         access_token_ttl_secs,
-        http_client,
-    };
+    )?;
 
     let (prometheus_layer, metric_handle) = PrometheusMetricLayer::pair();
 
@@ -222,23 +265,6 @@ pub fn build_gateway_with_settings(
 
     let session_router = crate::session::router::<GatewayState>().route_layer(csrf_middleware);
 
-    async fn csrf_token_handler(
-        session: tower_sessions::Session,
-    ) -> Result<Json<serde_json::Value>, crate::auth::error::AppError> {
-        let token = crate::csrf::get_or_create_token(&session)
-            .await
-            .map_err(|e| {
-                crate::auth::error::AppError::internal(
-                    "csrf token bootstrap",
-                    std::io::Error::other(e),
-                )
-            })?;
-        Ok(Json(serde_json::json!({
-            "csrf_token": token.as_str(),
-            "header": crate::csrf::TOKEN_HEADER,
-        })))
-    }
-
     let app = Router::new()
         .route("/auth/csrf", get(csrf_token_handler))
         .merge(login_router)
diff --git a/live-search/src/app.rs b/live-search/src/app.rs
index fdbf091..83f30aa 100644
--- a/live-search/src/app.rs
+++ b/live-search/src/app.rs
@@ -32,10 +32,6 @@ use crate::styles;
 /// # Errors
 /// Returns a server-function error for invalid input, unavailable application
 /// state, or a database failure.
-#[expect(
-    clippy::unused_async,
-    reason = "The server body is async only in the SSR build generated by #[server]"
-)]
 #[server(endpoint = "search")]
 pub async fn search(query: String) -> Result<Arc<Vec<SearchResult>>, ServerFnError> {
     #[cfg(feature = "ssr")]
@@ -120,6 +116,10 @@ pub fn shell(options: LeptosOptions) -> impl IntoView {
 }
 
 #[must_use]
+#[expect(
+    clippy::must_use_candidate,
+    reason = "Leptos #[component] generates a wrapper that nightly Clippy evaluates separately"
+)]
 #[component]
 pub fn App() -> impl IntoView {
     provide_meta_context();
@@ -150,6 +150,10 @@ pub fn App() -> impl IntoView {
     }
 }
 
+#[expect(
+    clippy::empty_enums,
+    reason = "Leptos #[component] generates an empty typed-builder state enum"
+)]
 #[component]
 fn SearchErrorBoundary(children: Children) -> impl IntoView {
     view! {
@@ -176,8 +180,8 @@ pub struct SearchResultRow {
 }
 
 #[expect(
-    clippy::missing_errors_doc,
-    reason = "Leptos component macro expansion looks fallible although the component API is not"
+    clippy::empty_enums,
+    reason = "Leptos #[component] generates an empty typed-builder state enum"
 )]
 #[component]
 fn TitleLinkCellRenderer(
@@ -211,6 +215,10 @@ fn result_row_renderer(
 }
 
 #[must_use]
+#[expect(
+    clippy::must_use_candidate,
+    reason = "Leptos #[component] generates a wrapper that nightly Clippy evaluates separately"
+)]
 #[component]
 pub fn SearchPage() -> impl IntoView {
     let (query, set_query) = signal(String::new());
@@ -325,117 +333,150 @@ struct LiveResult {
     snippet: Arc<str>,
 }
 
-#[must_use]
-#[component]
-pub fn LiveFeedPage() -> impl IntoView {
-    let results = RwSignal::new(VecDeque::<LiveResult>::new());
-    let connected = RwSignal::new(false);
-
-    #[cfg(target_arch = "wasm32")]
-    {
-        let stop = RwSignal::new(false);
-        let stop_cleanup = stop;
-        on_cleanup(move || stop_cleanup.set(true));
-
-        leptos::task::spawn_local(async move {
-            use futures::{StreamExt, stream};
-            use gloo_net::eventsource::State;
-            use gloo_timers::future::sleep;
-            use leptos::logging;
-            use std::time::Duration;
-
-            loop {
-                if stop.get() {
-                    logging::log!("SSE live feed stopped");
-                    return;
+#[cfg(target_arch = "wasm32")]
+fn apply_sse_event(
+    event: SseEvent,
+    results: RwSignal<VecDeque<LiveResult>>,
+    connected: RwSignal<bool>,
+) {
+    use leptos::logging;
+
+    match event {
+        SseEvent::Connected { .. } => connected.set(true),
+        SseEvent::SearchResult {
+            title,
+            url,
+            snippet,
+        } => {
+            results.update(|items| {
+                if items.len() >= 200 {
+                    items.pop_front();
                 }
+                items.push_back(LiveResult {
+                    title,
+                    url,
+                    snippet,
+                });
+            });
+        }
+        SseEvent::StreamLagged { skipped } => {
+            logging::warn!("SSE stream lagged by {skipped} messages");
+        }
+    }
+}
 
-                match gloo_net::eventsource::futures::EventSource::new("/api/events") {
-                    Ok(mut event_source) => {
-                        let connected_stream = event_source.subscribe("connected");
-                        let result_stream = event_source.subscribe("search_result");
-                        let lagged_stream = event_source.subscribe("stream_lagged");
-
-                        match (connected_stream, result_stream, lagged_stream) {
-                            (Ok(connected_events), Ok(result_events), Ok(lagged_events)) => {
-                                while event_source.state() == State::Connecting && !stop.get() {
-                                    sleep(Duration::from_millis(25)).await;
-                                }
+#[cfg(target_arch = "wasm32")]
+async fn consume_event_source(
+    event_source: &mut gloo_net::eventsource::futures::EventSource,
+    results: RwSignal<VecDeque<LiveResult>>,
+    connected: RwSignal<bool>,
+    stop: RwSignal<bool>,
+) {
+    use futures::{StreamExt, stream};
+    use gloo_net::eventsource::State;
+    use gloo_timers::future::sleep;
+    use leptos::logging;
+    use std::time::Duration;
+
+    let connected_stream = event_source.subscribe("connected");
+    let result_stream = event_source.subscribe("search_result");
+    let lagged_stream = event_source.subscribe("stream_lagged");
+    let (Ok(connected_events), Ok(result_events), Ok(lagged_events)) =
+        (connected_stream, result_stream, lagged_stream)
+    else {
+        logging::error!("Failed to subscribe to named SSE events");
+        return;
+    };
 
-                                if stop.get() {
-                                    return;
-                                }
+    while event_source.state() == State::Connecting && !stop.get() {
+        sleep(Duration::from_millis(25)).await;
+    }
+    if stop.get() {
+        return;
+    }
+    if event_source.state() != State::Open {
+        logging::warn!("SSE connection closed before opening");
+        return;
+    }
 
-                                if event_source.state() == State::Open {
-                                    let data_events = stream::select(result_events, lagged_events);
-                                    let mut all_events =
-                                        stream::select(connected_events, data_events);
-                                    while let Some(result) = all_events.next().await {
-                                        if stop.get() {
-                                            return;
-                                        }
-                                        match result {
-                                            Ok((_event_type, msg)) => {
-                                                let Some(data) = msg.data().as_string() else {
-                                                    logging::warn!(
-                                                        "SSE message had non-string data"
-                                                    );
-                                                    continue;
-                                                };
-                                                match serde_json::from_str::<SseEvent>(&data) {
-                                                    Ok(SseEvent::Connected { .. }) => {
-                                                        connected.set(true);
-                                                    }
-                                                    Ok(SseEvent::SearchResult {
-                                                        title,
-                                                        url,
-                                                        snippet,
-                                                    }) => {
-                                                        results.update(|r| {
-                                                            if r.len() >= 200 {
-                                                                r.pop_front();
-                                                            }
-                                                            r.push_back(LiveResult {
-                                                                title,
-                                                                url,
-                                                                snippet,
-                                                            });
-                                                        });
-                                                    }
-                                                    Ok(SseEvent::StreamLagged { skipped }) => {
-                                                        logging::warn!(
-                                                            "SSE stream lagged by {skipped} messages"
-                                                        );
-                                                    }
-                                                    Err(e) => {
-                                                        logging::warn!(
-                                                            "Invalid SSE message: {e:?}"
-                                                        );
-                                                    }
-                                                }
-                                            }
-                                            Err(e) => {
-                                                logging::warn!("SSE stream error: {e:?}");
-                                                break;
-                                            }
-                                        }
-                                    }
-                                } else {
-                                    logging::warn!("SSE connection closed before opening");
-                                }
-                            }
-                            _ => logging::error!("Failed to subscribe to named SSE events"),
-                        }
-                        connected.set(false);
-                        event_source.close();
-                    }
-                    Err(e) => logging::warn!("Failed to create EventSource: {e}"),
+    let data_events = stream::select(result_events, lagged_events);
+    let mut all_events = stream::select(connected_events, data_events);
+    while let Some(result) = all_events.next().await {
+        if stop.get() {
+            return;
+        }
+        match result {
+            Ok((_event_type, msg)) => {
+                let Some(data) = msg.data().as_string() else {
+                    logging::warn!("SSE message had non-string data");
+                    continue;
+                };
+                match serde_json::from_str::<SseEvent>(&data) {
+                    Ok(event) => apply_sse_event(event, results, connected),
+                    Err(error) => logging::warn!("Invalid SSE message: {error:?}"),
                 }
+            }
+            Err(error) => {
+                logging::warn!("SSE stream error: {error:?}");
+                return;
+            }
+        }
+    }
+}
 
-                sleep(Duration::from_secs(2)).await;
+#[cfg(target_arch = "wasm32")]
+async fn run_live_feed(
+    results: RwSignal<VecDeque<LiveResult>>,
+    connected: RwSignal<bool>,
+    stop: RwSignal<bool>,
+) {
+    use gloo_net::eventsource::futures::EventSource;
+    use gloo_timers::future::sleep;
+    use leptos::logging;
+    use std::time::Duration;
+
+    loop {
+        if stop.get() {
+            logging::log!("SSE live feed stopped");
+            return;
+        }
+
+        match EventSource::new("/api/events") {
+            Ok(mut event_source) => {
+                consume_event_source(&mut event_source, results, connected, stop).await;
+                connected.set(false);
+                event_source.close();
             }
-        });
+            Err(error) => logging::warn!("Failed to create EventSource: {error}"),
+        }
+
+        if stop.get() {
+            return;
+        }
+        sleep(Duration::from_secs(2)).await;
     }
+}
+
+#[cfg(target_arch = "wasm32")]
+fn start_live_feed(results: RwSignal<VecDeque<LiveResult>>, connected: RwSignal<bool>) {
+    let stop = RwSignal::new(false);
+    let stop_cleanup = stop;
+    on_cleanup(move || stop_cleanup.set(true));
+    leptos::task::spawn_local(run_live_feed(results, connected, stop));
+}
+
+#[must_use]
+#[expect(
+    clippy::must_use_candidate,
+    reason = "Leptos #[component] generates a wrapper that nightly Clippy evaluates separately"
+)]
+#[component]
+pub fn LiveFeedPage() -> impl IntoView {
+    let results = RwSignal::new(VecDeque::<LiveResult>::new());
+    let connected = RwSignal::new(false);
+
+    #[cfg(target_arch = "wasm32")]
+    start_live_feed(results, connected);
 
     view! {
         <h2>"Live Feed"</h2>
@@ -465,12 +506,12 @@ pub fn LiveFeedPage() -> impl IntoView {
                 } else {
                     items
                         .iter()
-                        .map(|r| {
+                        .map(|result| {
                             view! {
                                 <div class=styles::result_item data-testid="live-result">
-                                    <h3 class=styles::result_title>{r.title.clone()}</h3>
-                                    <p class=styles::result_snippet>{r.snippet.clone()}</p>
-                                    <small class=styles::result_url>{r.url.clone()}</small>
+                                    <h3 class=styles::result_title>{result.title.clone()}</h3>
+                                    <p class=styles::result_snippet>{result.snippet.clone()}</p>
+                                    <small class=styles::result_url>{result.url.clone()}</small>
                                 </div>
                             }
                         })
diff --git a/live-search/src/bootstrap.rs b/live-search/src/bootstrap.rs
index 4eb2ed2..7f119b8 100644
--- a/live-search/src/bootstrap.rs
+++ b/live-search/src/bootstrap.rs
@@ -100,6 +100,32 @@ async fn fallback_handler(uri: Uri) -> impl IntoResponse {
     (StatusCode::NOT_FOUND, format!("Not found: {uri}"))
 }
 
+fn spawn_pg_listener(
+    tasks: &mut JoinSet<anyhow::Result<()>>,
+    pool: sqlx::PgPool,
+    tx: broadcast::Sender<SseEvent>,
+    cache: CacheHandle,
+    shutdown: CancellationToken,
+) {
+    let listener_span = tracing::info_span!("pg_listener");
+    tasks.spawn(
+        async move {
+            db::run_pg_listener(pool, tx, cache, shutdown).await;
+            Ok(())
+        }
+        .instrument(listener_span),
+    );
+}
+
+fn listener_addr(default_port: u16) -> SocketAddr {
+    let port = std::env::var("PORT")
+        .or_else(|_| std::env::var("LIVE_SEARCH_PORT"))
+        .ok()
+        .and_then(|value| value.parse().ok())
+        .unwrap_or(default_port);
+    SocketAddr::from(([0, 0, 0, 0], port))
+}
+
 /// Bootstraps all subsystems and starts the HTTP server.
 ///
 /// # Errors
@@ -150,16 +176,12 @@ pub async fn run() -> anyhow::Result<ServerHandle> {
     let shutdown = CancellationToken::new();
     let mut tasks = JoinSet::new();
 
-    let listener_token = shutdown.child_token();
-    let pool_for_listener = raw_pool.clone();
-    let listener_span = tracing::info_span!("pg_listener");
-    let cache_for_listener = cache_handle.clone();
-    tasks.spawn(
-        async move {
-            db::run_pg_listener(pool_for_listener, tx, cache_for_listener, listener_token).await;
-            Ok(())
-        }
-        .instrument(listener_span),
+    spawn_pg_listener(
+        &mut tasks,
+        raw_pool.clone(),
+        tx,
+        cache_handle.clone(),
+        shutdown.child_token(),
     );
 
     let conf = get_configuration(None).context("failed to read Leptos configuration")?;
@@ -217,12 +239,7 @@ pub async fn run() -> anyhow::Result<ServerHandle> {
 
     let router: Router<()> = router.with_state(leptos_options);
 
-    let port: u16 = std::env::var("PORT")
-        .or_else(|_| std::env::var("LIVE_SEARCH_PORT"))
-        .ok()
-        .and_then(|p| p.parse().ok())
-        .unwrap_or(cfg.live_search.port);
-    let addr = SocketAddr::from(([0, 0, 0, 0], port));
+    let addr = listener_addr(cfg.live_search.port);
     tracing::info!("Live search server listening on {addr}");
 
     let listener = tokio::net::TcpListener::bind(addr)

From d42ad52bdf1b4a96ab6e79a0033027635e101843 Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 12:45:23 +0200
Subject: [PATCH 02/17] fix: finish strict nightly lint cleanup

---
 live-search/src/app.rs | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/live-search/src/app.rs b/live-search/src/app.rs
index 83f30aa..9610f59 100644
--- a/live-search/src/app.rs
+++ b/live-search/src/app.rs
@@ -22,6 +22,11 @@ use crate::db::SearchResult;
 use crate::events::SseEvent;
 use crate::styles;
 
+#[expect(
+    clippy::empty_enums,
+    reason = "Leptos #[component] typed-builder macro generates empty state enums in this module"
+)]
+
 /// Search `search_results` using PostgreSQL FTS with a trigram fallback.
 ///
 /// The `title % $1` branch is backed by the `pg_trgm` GIN index created by
@@ -150,10 +155,6 @@ pub fn App() -> impl IntoView {
     }
 }
 
-#[expect(
-    clippy::empty_enums,
-    reason = "Leptos #[component] generates an empty typed-builder state enum"
-)]
 #[component]
 fn SearchErrorBoundary(children: Children) -> impl IntoView {
     view! {
@@ -179,10 +180,6 @@ pub struct SearchResultRow {
     pub url: String,
 }
 
-#[expect(
-    clippy::empty_enums,
-    reason = "Leptos #[component] generates an empty typed-builder state enum"
-)]
 #[component]
 fn TitleLinkCellRenderer(
     class: String,

From ab8bac5910171adaa4833967c99d5d5f9cf3ece8 Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 12:46:07 +0200
Subject: [PATCH 03/17] fix: remove unnecessary gateway mutability

---
 gateway/src/gateway.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gateway/src/gateway.rs b/gateway/src/gateway.rs
index a61389d..ab45581 100644
--- a/gateway/src/gateway.rs
+++ b/gateway/src/gateway.rs
@@ -172,7 +172,7 @@ fn gateway_state(
 #[instrument(skip(modules, settings, db_pool))]
 pub fn build_gateway_with_settings(
     modules: Vec<Arc<dyn ServiceModule>>,
-    mut settings: settings::Settings,
+    settings: settings::Settings,
     proxy_upstream_url: String,
     db_pool: Option<sqlx::PgPool>,
     refresh_token_ttl_secs: i64,

From fe7c0507d4a0bd6aa6bc3091acb4a8a487f26238 Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 12:48:25 +0200
Subject: [PATCH 04/17] fix: address remaining strict nightly diagnostics

---
 live-search/src/app.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/live-search/src/app.rs b/live-search/src/app.rs
index 9610f59..f629618 100644
--- a/live-search/src/app.rs
+++ b/live-search/src/app.rs
@@ -4,6 +4,11 @@
 //! - `/` — [`SearchPage`] with full-text + trigram search.
 //! - `/live` — [`LiveFeedPage`] with named Server-Sent Events.
 
+#![expect(
+    clippy::empty_enums,
+    reason = "Leptos #[component] typed-builder macro generates empty state enums in this module"
+)]
+
 use std::collections::VecDeque;
 use std::sync::Arc;
 

From 59fc6a2edf635be8c4e8ad461d261b262c9dd48f Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 13:05:20 +0200
Subject: [PATCH 05/17] fix: address final strict nightly diagnostics

---
 live-search/src/app.rs       |  5 -----
 live-search/src/bootstrap.rs | 26 +++++++++++++++-----------
 2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/live-search/src/app.rs b/live-search/src/app.rs
index f629618..924cb29 100644
--- a/live-search/src/app.rs
+++ b/live-search/src/app.rs
@@ -27,11 +27,6 @@ use crate::db::SearchResult;
 use crate::events::SseEvent;
 use crate::styles;
 
-#[expect(
-    clippy::empty_enums,
-    reason = "Leptos #[component] typed-builder macro generates empty state enums in this module"
-)]
-
 /// Search `search_results` using PostgreSQL FTS with a trigram fallback.
 ///
 /// The `title % $1` branch is backed by the `pg_trgm` GIN index created by
diff --git a/live-search/src/bootstrap.rs b/live-search/src/bootstrap.rs
index 7f119b8..bcb8475 100644
--- a/live-search/src/bootstrap.rs
+++ b/live-search/src/bootstrap.rs
@@ -126,6 +126,20 @@ fn listener_addr(default_port: u16) -> SocketAddr {
     SocketAddr::from(([0, 0, 0, 0], port))
 }
 
+fn database_settings(config: &rwf_config::Config) -> (String, db::PoolTunables) {
+    let database_url = std::env::var("DATABASE_URL")
+        .ok()
+        .unwrap_or_else(|| config.live_search.database_url.clone());
+    let pool_tunables = db::PoolTunables {
+        max_connections: config.live_search.pool_max_connections,
+        min_connections: config.live_search.pool_min_connections,
+        acquire_timeout_secs: config.live_search.pool_acquire_timeout_secs,
+        idle_timeout_secs: config.live_search.pool_idle_timeout_secs,
+        max_lifetime_secs: config.live_search.pool_max_lifetime_secs,
+    };
+    (database_url, pool_tunables)
+}
+
 /// Bootstraps all subsystems and starts the HTTP server.
 ///
 /// # Errors
@@ -135,17 +149,7 @@ pub async fn run() -> anyhow::Result<ServerHandle> {
     init_tracing();
 
     let cfg = rwf_config::Config::load().context("failed to load workspace config")?;
-    let database_url = std::env::var("DATABASE_URL")
-        .ok()
-        .unwrap_or_else(|| cfg.live_search.database_url.clone());
-
-    let pool_tunables = db::PoolTunables {
-        max_connections: cfg.live_search.pool_max_connections,
-        min_connections: cfg.live_search.pool_min_connections,
-        acquire_timeout_secs: cfg.live_search.pool_acquire_timeout_secs,
-        idle_timeout_secs: cfg.live_search.pool_idle_timeout_secs,
-        max_lifetime_secs: cfg.live_search.pool_max_lifetime_secs,
-    };
+    let (database_url, pool_tunables) = database_settings(&cfg);
     tracing::info!("{}", cfg.live_search.connection_budget_summary());
 
     let raw_pool = db::create_pool(&database_url, &pool_tunables)

From 4a7d5d7fff4f43c4a1b98173abfc11a92883d27f Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 13:09:54 +0200
Subject: [PATCH 06/17] fix: satisfy strict e2e lint checks

---
 e2e-tests/src/common/chromium.rs | 8 +++++---
 e2e-tests/src/common/db.rs       | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/e2e-tests/src/common/chromium.rs b/e2e-tests/src/common/chromium.rs
index c7f70b0..5ceed7c 100644
--- a/e2e-tests/src/common/chromium.rs
+++ b/e2e-tests/src/common/chromium.rs
@@ -171,9 +171,11 @@ pub async fn setup() -> Result<TestContext> {
 }
 
 /// Tear down a [`TestContext`] by closing the page and browser in reverse
-/// creation order. Cleanup errors are logged via `eprintln!` (stderr,
-/// captured by the test harness per-test and displayed only on failure)
-/// but never mask the test assertion that already ran.
+/// creation order.
+///
+/// Cleanup errors are logged via `eprintln!` (stderr, captured by the test
+/// harness per-test and displayed only on failure), but never mask the test
+/// assertion that already ran.
 pub async fn teardown(ctx: TestContext) {
     let TestContext {
         mut browser,
diff --git a/e2e-tests/src/common/db.rs b/e2e-tests/src/common/db.rs
index ba487ba..6e57cde 100644
--- a/e2e-tests/src/common/db.rs
+++ b/e2e-tests/src/common/db.rs
@@ -22,7 +22,7 @@ impl std::fmt::Debug for TestEnv {
         f.debug_struct("TestEnv")
             .field("pool", &self.pool)
             .field("connection_string", &self.connection_string)
-            .field("container", &"<container>")
+            .field("_container", &"<container>")
             .finish()
     }
 }

From bcfa1bc5e68024038242c1b8d9ed41d497ec6942 Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 13:18:30 +0200
Subject: [PATCH 07/17] refactor: split SSE e2e test helpers

---
 e2e-tests/tests/sse_test.rs | 246 ++++++++++++++++++------------------
 1 file changed, 120 insertions(+), 126 deletions(-)

diff --git a/e2e-tests/tests/sse_test.rs b/e2e-tests/tests/sse_test.rs
index caf06d4..249eefc 100644
--- a/e2e-tests/tests/sse_test.rs
+++ b/e2e-tests/tests/sse_test.rs
@@ -12,7 +12,7 @@ use std::time::Duration;
 
 use anyhow::Context;
 use e2e_tests::common::{LiveSearchEnv, SharedServer};
-use futures::StreamExt;
+use futures::{Stream, StreamExt};
 
 /// Shared live-search server instance, initialised lazily on first access.
 static SERVER: SharedServer<LiveSearchEnv> = SharedServer::new();
@@ -32,6 +32,80 @@ fn test_client() -> anyhow::Result<reqwest::Client> {
         .context("failed to build reqwest client")
 }
 
+fn unique_test_title(prefix: &str) -> String {
+    format!(
+        "{prefix}-{}-{}",
+        std::process::id(),
+        std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .map_or(0, |duration| duration.as_nanos())
+    )
+}
+
+async fn insert_search_result(
+    pool: &sqlx::PgPool,
+    title: &str,
+    url: &str,
+    snippet: &str,
+    context: &'static str,
+) -> anyhow::Result<()> {
+    sqlx::query("INSERT INTO search_results (title, url, snippet) VALUES ($1, $2, $3)")
+        .bind(title)
+        .bind(url)
+        .bind(snippet)
+        .execute(pool)
+        .await
+        .context(context)?;
+    Ok(())
+}
+
+async fn wait_for_search_result<S, B, E>(
+    stream: &mut S,
+    buffer: &mut String,
+    title: &str,
+    phase: &str,
+    poll_timeout: Duration,
+) -> anyhow::Result<()>
+where
+    S: Stream<Item = Result<B, E>> + Unpin,
+    B: AsRef<[u8]>,
+    E: std::fmt::Display,
+{
+    let deadline = tokio::time::Instant::now() + Duration::from_secs(10);
+    loop {
+        if tokio::time::Instant::now() >= deadline {
+            anyhow::bail!(
+                "Timeout waiting for {phase} SSE event. Buffer so far (first 500 chars): {buffer:.500}"
+            );
+        }
+
+        match tokio::time::timeout(poll_timeout, stream.next()).await {
+            Ok(Some(Ok(chunk))) => {
+                buffer.push_str(&String::from_utf8_lossy(chunk.as_ref()));
+                buffer.push('\n');
+                if buffer.contains(title) && buffer.contains("SearchResult") {
+                    return Ok(());
+                }
+            }
+            Ok(Some(Err(error))) => anyhow::bail!("SSE stream error during {phase}: {error}"),
+            Ok(None) => {
+                anyhow::bail!("SSE stream ended during {phase}. Buffer: {buffer:.300}");
+            }
+            Err(_) => {}
+        }
+    }
+}
+
+async fn cleanup_test_row(pool: &sqlx::PgPool, title: &str, label: &str) {
+    if let Err(error) = sqlx::query("DELETE FROM search_results WHERE title = $1")
+        .bind(title)
+        .execute(pool)
+        .await
+    {
+        eprintln!("warning: failed to delete {label} row '{title}': {error}");
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Required integration tests (from spec)
 // ---------------------------------------------------------------------------
@@ -85,13 +159,11 @@ async fn notify_trigger_fires_sse_event() -> anyhow::Result<()> {
         .await
         .with_context(|| format!("failed to connect to {conn_str}"))?;
 
-    // ── 0. Pre-clean: wipe any leftover e2e-test rows from previous failed runs.
     sqlx::query("DELETE FROM search_results WHERE title LIKE 'e2e-%' OR title LIKE 'e2e-warmup-%' OR title LIKE 'browser-sse-sentinel-%'")
         .execute(&pool)
         .await
         .ok();
 
-    // ── 1. Open an SSE connection to /api/events ──────────────────────
     let client = test_client()?;
     let url = format!("{}/api/events", env.base_url());
     let response = client
@@ -99,138 +171,60 @@ async fn notify_trigger_fires_sse_event() -> anyhow::Result<()> {
         .send()
         .await
         .with_context(|| format!("failed to GET {url}"))?;
-
     assert_eq!(response.status(), 200);
+
     let mut stream = response.bytes_stream();
-    let mut buf = String::new();
+    let mut buffer = String::new();
 
-    // ── 2. Insert a warmup row and wait for it to appear in the stream ─
-    //
-    // PostgreSQL NOTIFY is best-effort: if `PgListener` hasn't yet called
-    // `LISTEN search_results` (cold start, slow CI runner), the NOTIFY is
-    // dropped silently and the assertion below would time out for the wrong
-    // reason. We can't observe `PgListener::listen()` directly, but we CAN
-    // prove the listener is active by inserting a sentinel row and waiting
-    // for the resulting SSE event. (Waiting for `SseEvent::Connected` is
-    // NOT sufficient — that event is emitted by the SSE handler itself,
-    // independent of the broadcast/listener pipeline.)
-    let warmup_title = format!(
-        "e2e-warmup-{}-{}",
-        std::process::id(),
-        std::time::SystemTime::now()
-            .duration_since(std::time::UNIX_EPOCH)
-            .map_or(0, |d| d.as_nanos())
-    );
+    // PostgreSQL NOTIFY is best-effort, so first prove PgListener has reached
+    // LISTEN before inserting the row whose event the test actually asserts.
+    let warmup_title = unique_test_title("e2e-warmup");
     let warmup_url = format!("https://example.com/e2e-warmup/{warmup_title}");
-    sqlx::query("INSERT INTO search_results (title, url, snippet) VALUES ($1, $2, $3)")
-        .bind(&warmup_title)
-        .bind(&warmup_url)
-        .bind("SSE warmup row to prove PgListener is LISTEN-ing")
-        .execute(&pool)
-        .await
-        .context("failed to insert warmup row")?;
-
-    let warmup_deadline = tokio::time::Instant::now() + Duration::from_secs(10);
-    loop {
-        assert!(
-            tokio::time::Instant::now() < warmup_deadline,
-            "Timeout waiting for warmup SSE event — PgListener may not be \
-             LISTEN-ing yet. Buffer so far (first 500 chars): {buf:.500}"
-        );
-        match tokio::time::timeout(Duration::from_secs(1), stream.next()).await {
-            Ok(Some(Ok(chunk))) => {
-                buf.push_str(&String::from_utf8_lossy(&chunk));
-                buf.push('\n');
-                if buf.contains(&warmup_title) && buf.contains("SearchResult") {
-                    break;
-                }
-            }
-            Ok(Some(Err(e))) => return Err(anyhow::anyhow!("SSE stream error during warmup: {e}")),
-            Ok(None) => {
-                return Err(anyhow::anyhow!(
-                    "SSE stream ended during warmup. Buffer: {buf:.300}"
-                ));
-            }
-            Err(_timeout) => {} // keep waiting
-        }
-    }
+    insert_search_result(
+        &pool,
+        &warmup_title,
+        &warmup_url,
+        "SSE warmup row to prove PgListener is LISTEN-ing",
+        "failed to insert warmup row",
+    )
+    .await?;
+    wait_for_search_result(
+        &mut stream,
+        &mut buffer,
+        &warmup_title,
+        "warmup",
+        Duration::from_secs(1),
+    )
+    .await?;
     println!("Warmup SSE event received — PgListener is LISTEN-ing");
 
-    // ── 3. Insert the real test row ──────────────────────────────────
-    let title = format!(
-        "e2e-test-{}-{}",
-        std::process::id(),
-        std::time::SystemTime::now()
-            .duration_since(std::time::UNIX_EPOCH)
-            .map_or(0, |d| d.as_nanos())
-    );
-    // Use a unique URL per test run so the UNIQUE constraint on `url` does
-    // not reject the INSERT when the test is re-run.
+    let title = unique_test_title("e2e-test");
     let test_url = format!("https://example.com/e2e-test/{title}");
-    let snippet = "E2E test snippet for NOTIFY→SSE verification";
+    insert_search_result(
+        &pool,
+        &title,
+        &test_url,
+        "E2E test snippet for NOTIFY→SSE verification",
+        "failed to insert search result",
+    )
+    .await?;
+    wait_for_search_result(
+        &mut stream,
+        &mut buffer,
+        &title,
+        "SearchResult",
+        Duration::from_secs(2),
+    )
+    .await?;
+    println!("SearchResult SSE event with title '{title}' received");
 
-    sqlx::query("INSERT INTO search_results (title, url, snippet) VALUES ($1, $2, $3)")
-        .bind(&title)
-        .bind(&test_url)
-        .bind(snippet)
-        .execute(&pool)
-        .await
-        .context("failed to insert search result")?;
-
-    // ── 4. Read SSE events until we see the SearchResult ──────────────
-    let deadline = tokio::time::Instant::now() + Duration::from_secs(10);
-    loop {
-        assert!(
-            tokio::time::Instant::now() < deadline,
-            "Timeout waiting for SearchResult SSE event. \
-             Buffer so far (first 500 chars): {buf:.500}"
-        );
-        match tokio::time::timeout(Duration::from_secs(2), stream.next()).await {
-            Ok(Some(Ok(chunk))) => {
-                buf.push_str(&String::from_utf8_lossy(&chunk));
-                buf.push('\n');
-                if buf.contains(&title) && buf.contains("SearchResult") {
-                    println!("SearchResult SSE event with title '{title}' received");
-
-                    // Snapshot the event payload for regression detection.
-                    // Fields like `title`, `url`, `snippet` contain the
-                    // inserted values — the snapshot captures the shape.
-                    if let Some(event_json) = parse_sse_json_payload(&buf, &title) {
-                        // unwrap is safe: to_string_pretty only fails on
-                        // non-finite floats, which serde_json::Value from a
-                        // known schema never contains.
-                        event_snapshot(event_json);
-                    }
-
-                    // Best-effort cleanup so re-runs don't accumulate rows.
-                    if let Err(e) = sqlx::query("DELETE FROM search_results WHERE title = $1")
-                        .bind(&title)
-                        .execute(&pool)
-                        .await
-                    {
-                        eprintln!("warning: failed to delete e2e-test row '{title}': {e}");
-                    }
-                    if let Err(e) = sqlx::query("DELETE FROM search_results WHERE title = $1")
-                        .bind(&warmup_title)
-                        .execute(&pool)
-                        .await
-                    {
-                        eprintln!("warning: failed to delete e2e-warmup row '{warmup_title}': {e}");
-                    }
-                    return Ok(());
-                }
-            }
-            Ok(Some(Err(e))) => return Err(anyhow::anyhow!("SSE stream error: {e}")),
-            Ok(None) => {
-                return Err(anyhow::anyhow!(
-                    "SSE stream ended before SearchResult. Buffer: {buf:.300}"
-                ));
-            }
-            Err(_timeout) => {
-                // No data in this 2 s window — keep waiting.
-            }
-        }
+    if let Some(event_json) = parse_sse_json_payload(&buffer, &title) {
+        event_snapshot(event_json);
     }
+
+    cleanup_test_row(&pool, &title, "e2e-test").await;
+    cleanup_test_row(&pool, &warmup_title, "e2e-warmup").await;
+    Ok(())
 }
 
 /// Try to extract the SSE event JSON for the test row from the accumulated

From bf87da6e0f724d9e8841135c802c9b981dbe43e0 Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 13:22:24 +0200
Subject: [PATCH 08/17] ci: align native Clippy with strict lint groups

---
 .github/workflows/ci.yml | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cb33f58..2fad14f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -139,11 +139,12 @@ jobs:
             clippy-target-v2-${{ runner.os }}-rust-1.98.1-
       - name: Clippy
         run: |
-          cargo +1.98.1 clippy --locked --workspace --all-targets -- -D warnings
-          cargo +1.98.1 clippy --locked -p live-search --features ssr --all-targets -- -D warnings
-          cargo +1.98.1 clippy --locked -p live-search --features ssr,otel --all-targets -- -D warnings
-          cargo +1.98.1 clippy --locked -p gateway-example --features otel --all-targets -- -D warnings
-          cargo +1.98.1 clippy --locked -p i18n-demo --features ssr --all-targets -- -D warnings
+          lint_args=(-D warnings -D clippy::pedantic -D clippy::nursery)
+          cargo +1.98.1 clippy --locked --workspace --all-targets -- "${lint_args[@]}"
+          cargo +1.98.1 clippy --locked -p live-search --features ssr --all-targets -- "${lint_args[@]}"
+          cargo +1.98.1 clippy --locked -p live-search --features ssr,otel --all-targets -- "${lint_args[@]}"
+          cargo +1.98.1 clippy --locked -p gateway-example --features otel --all-targets -- "${lint_args[@]}"
+          cargo +1.98.1 clippy --locked -p i18n-demo --features ssr --all-targets -- "${lint_args[@]}"
       - name: Report Clippy cache footprint
         if: always()
         run: du -sh target/debug 2>/dev/null || true

From b8c9a15b8db2ddc752412daae9453d01f855098f Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 13:24:17 +0200
Subject: [PATCH 09/17] fix: use pedantic-friendly result assertion

---
 e2e-tests/tests/live_search_test.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/e2e-tests/tests/live_search_test.rs b/e2e-tests/tests/live_search_test.rs
index 65fd27a..978e27e 100644
--- a/e2e-tests/tests/live_search_test.rs
+++ b/e2e-tests/tests/live_search_test.rs
@@ -323,7 +323,7 @@ async fn server_fn_search_returns_results_via_http() -> anyhow::Result<()> {
     let results = json
         .as_array()
         .context("server fn response should be a JSON array")?;
-    assert!(!results.is_empty());
+    assert_ne!(results.len(), 0, "search should return at least one result");
     assert!(results.iter().any(|row| {
         row.get("title")
             .and_then(serde_json::Value::as_str)

From 42f21363a26fe22da999824a69b4845b9d7b6367 Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 13:37:48 +0200
Subject: [PATCH 10/17] fix: bound strict lint exemptions to generated i18n
 code

---
 i18n-demo/build.rs     | 10 +++++++---
 i18n-demo/src/app.rs   |  8 ++++++++
 live-search/src/app.rs |  5 -----
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/i18n-demo/build.rs b/i18n-demo/build.rs
index b968f2a..9e86abb 100644
--- a/i18n-demo/build.rs
+++ b/i18n-demo/build.rs
@@ -26,12 +26,16 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     translations_infos.rerun_if_locales_changed();
 
-    // Suppress style-only Clippy noise in third-party generated source. The
-    // strict gate still forbids unwrap/expect/panic/unsafe-policy lints, so
-    // generated code cannot waive those non-negotiable categories.
+    // Bound Clippy exemptions to third-party generated source. Handwritten
+    // source remains governed by rust-skills2's source-policy pass; this
+    // generated module necessarily contains its own allow attributes, locale
+    // parse expects, and typed-builder empty enums.
     let top_level_attrs: proc_macro2::TokenStream = concat!(
         "#![allow(",
         "clippy::allow_attributes, ",
+        "clippy::allow_attributes_without_reason, ",
+        "clippy::expect_used, ",
+        "clippy::empty_enums, ",
         "clippy::pedantic, ",
         "clippy::module_inception, ",
         "clippy::use_self, ",
diff --git a/i18n-demo/src/app.rs b/i18n-demo/src/app.rs
index a42183a..ebf8fae 100644
--- a/i18n-demo/src/app.rs
+++ b/i18n-demo/src/app.rs
@@ -49,6 +49,10 @@ fn set_document_lang(lang: &str) {
 const fn set_document_lang(_lang: &str) {}
 
 #[must_use]
+#[expect(
+    clippy::must_use_candidate,
+    reason = "Leptos #[component] generates a wrapper that nightly Clippy evaluates separately"
+)]
 #[component]
 pub fn App() -> impl IntoView {
     provide_meta_context();
@@ -70,6 +74,10 @@ pub fn App() -> impl IntoView {
 }
 
 #[must_use]
+#[expect(
+    clippy::must_use_candidate,
+    reason = "Leptos #[component] generates a wrapper that nightly Clippy evaluates separately"
+)]
 #[component]
 pub fn Home() -> impl IntoView {
     let i18n = use_i18n();
diff --git a/live-search/src/app.rs b/live-search/src/app.rs
index 924cb29..d3d8e53 100644
--- a/live-search/src/app.rs
+++ b/live-search/src/app.rs
@@ -4,11 +4,6 @@
 //! - `/` — [`SearchPage`] with full-text + trigram search.
 //! - `/live` — [`LiveFeedPage`] with named Server-Sent Events.
 
-#![expect(
-    clippy::empty_enums,
-    reason = "Leptos #[component] typed-builder macro generates empty state enums in this module"
-)]
-
 use std::collections::VecDeque;
 use std::sync::Arc;
 

From 51bd2ed18399fa87faf24af5c84337280b4cdb2f Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 13:41:13 +0200
Subject: [PATCH 11/17] fix: scope Leptos empty-enum expectations

---
 live-search/src/app.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/live-search/src/app.rs b/live-search/src/app.rs
index d3d8e53..83f30aa 100644
--- a/live-search/src/app.rs
+++ b/live-search/src/app.rs
@@ -150,6 +150,10 @@ pub fn App() -> impl IntoView {
     }
 }
 
+#[expect(
+    clippy::empty_enums,
+    reason = "Leptos #[component] generates an empty typed-builder state enum"
+)]
 #[component]
 fn SearchErrorBoundary(children: Children) -> impl IntoView {
     view! {
@@ -175,6 +179,10 @@ pub struct SearchResultRow {
     pub url: String,
 }
 
+#[expect(
+    clippy::empty_enums,
+    reason = "Leptos #[component] generates an empty typed-builder state enum"
+)]
 #[component]
 fn TitleLinkCellRenderer(
     class: String,

From abb0847f36a80bf6075e1a37c9b7c214854becaf Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 13:48:20 +0200
Subject: [PATCH 12/17] fix: propagate Leptos lint expectations through
 component macro

---
 live-search/src/app.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/live-search/src/app.rs b/live-search/src/app.rs
index 83f30aa..8a57d72 100644
--- a/live-search/src/app.rs
+++ b/live-search/src/app.rs
@@ -150,11 +150,11 @@ pub fn App() -> impl IntoView {
     }
 }
 
+#[component]
 #[expect(
     clippy::empty_enums,
     reason = "Leptos #[component] generates an empty typed-builder state enum"
 )]
-#[component]
 fn SearchErrorBoundary(children: Children) -> impl IntoView {
     view! {
         <ErrorBoundary fallback=move |_errors| {
@@ -179,11 +179,11 @@ pub struct SearchResultRow {
     pub url: String,
 }
 
+#[component]
 #[expect(
     clippy::empty_enums,
     reason = "Leptos #[component] generates an empty typed-builder state enum"
 )]
-#[component]
 fn TitleLinkCellRenderer(
     class: String,
     value: Signal<String>,

From 9ad6f1504d4cf8850b26a604c46caf16b4824104 Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 13:55:16 +0200
Subject: [PATCH 13/17] refactor: remove unnecessary Leptos component wrappers

---
 live-search/src/app.rs | 64 +++++++++++++-----------------------------
 1 file changed, 20 insertions(+), 44 deletions(-)

diff --git a/live-search/src/app.rs b/live-search/src/app.rs
index 8a57d72..f9c5816 100644
--- a/live-search/src/app.rs
+++ b/live-search/src/app.rs
@@ -150,28 +150,10 @@ pub fn App() -> impl IntoView {
     }
 }
 
-#[component]
-#[expect(
-    clippy::empty_enums,
-    reason = "Leptos #[component] generates an empty typed-builder state enum"
-)]
-fn SearchErrorBoundary(children: Children) -> impl IntoView {
-    view! {
-        <ErrorBoundary fallback=move |_errors| {
-            view! {
-                <div class="error-boundary" data-testid="error-boundary">
-                    <h3>"Something went wrong."</h3>
-                    <p>"Try reloading the page to recover."</p>
-                </div>
-            }
-        }>{children()}</ErrorBoundary>
-    }
-}
-
 #[derive(Debug, TableRow, Clone)]
 #[table(impl_vec_data_provider)]
 pub struct SearchResultRow {
-    #[table(title = "Title", renderer = "TitleLinkCellRenderer")]
+    #[table(title = "Title")]
     pub title: String,
     #[table(title = "Snippet")]
     pub snippet: String,
@@ -179,37 +161,24 @@ pub struct SearchResultRow {
     pub url: String,
 }
 
-#[component]
-#[expect(
-    clippy::empty_enums,
-    reason = "Leptos #[component] generates an empty typed-builder state enum"
-)]
-fn TitleLinkCellRenderer(
-    class: String,
-    value: Signal<String>,
-    row: RwSignal<SearchResultRow>,
-    index: usize,
-) -> impl IntoView {
-    let _ = index;
-    let url = move || row.read().url.clone();
-    view! {
-        <td class=class>
-            <a href=url>{value}</a>
-        </td>
-    }
-}
-
 fn result_row_renderer(
     class: Signal<String>,
     row: RwSignal<SearchResultRow>,
-    index: usize,
+    _index: usize,
     _selected: Signal<bool>,
     on_select: EventHandler<leptos::web_sys::MouseEvent>,
-    columns: RwSignal<Vec<usize>>,
+    _columns: RwSignal<Vec<usize>>,
 ) -> impl IntoView {
+    let row = row.get_untracked();
+    let title = row.title;
+    let snippet = row.snippet;
+    let url = row.url;
+
     view! {
         <tr class=class data-testid="result-item" on:click=move |ev| on_select.run(ev)>
-            {SearchResultRow::render_row(row, index, columns)}
+            <td><a href=url.clone()>{title}</a></td>
+            <td>{snippet}</td>
+            <td>{url}</td>
         </tr>
     }
 }
@@ -272,7 +241,14 @@ pub fn SearchPage() -> impl IntoView {
             </button>
         </form>
 
-        <SearchErrorBoundary>
+        <ErrorBoundary fallback=move |_errors| {
+            view! {
+                <div class="error-boundary" data-testid="error-boundary">
+                    <h3>"Something went wrong."</h3>
+                    <p>"Try reloading the page to recover."</p>
+                </div>
+            }
+        }>
             <div id="results">
                 <Show when=move || !has_query() fallback=|| ()>
                     <p>"Enter a query above to search."</p>
@@ -322,7 +298,7 @@ pub fn SearchPage() -> impl IntoView {
                         })
                 }}
             </div>
-        </SearchErrorBoundary>
+        </ErrorBoundary>
     }
 }
 

From 7c41e4884b102bf37a1e90c39104e0d12ec98d83 Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 14:51:00 +0200
Subject: [PATCH 14/17] fix: remove strict-gate manifest warnings

---
 e2e-tests/Cargo.toml   | 8 +++-----
 gateway/Cargo.toml     | 1 -
 i18n-demo/Cargo.toml   | 7 +++----
 live-search/Cargo.toml | 5 ++---
 live-search/src/app.rs | 4 +++-
 5 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/e2e-tests/Cargo.toml b/e2e-tests/Cargo.toml
index 158fb6f..13f9953 100644
--- a/e2e-tests/Cargo.toml
+++ b/e2e-tests/Cargo.toml
@@ -78,8 +78,7 @@ opentelemetry_sdk = { workspace = true, optional = true, features = ["testing"]
 # Test infrastructure
 testcontainers = { workspace = true }
 
-# Snapshot testing & property-based testing
-insta = { workspace = true, features = ["json"] }
+# Property-based test helpers are used by the shared test-support library.
 proptest = { workspace = true }
 
 # Shared domain types (SearchResult, etc.)
@@ -99,6 +98,5 @@ chrono = { workspace = true }
 uuid = { workspace = true }
 
 [dev-dependencies]
-# Anything extra that only the integration tests need (not the lib helpers).
-# Currently empty — every dep that test binaries need is already a regular
-# dependency, reachable through the library crate.
+# Snapshot assertions are used only by integration-test binaries.
+insta = { workspace = true, features = ["json"] }
diff --git a/gateway/Cargo.toml b/gateway/Cargo.toml
index 93929af..3b370ee 100644
--- a/gateway/Cargo.toml
+++ b/gateway/Cargo.toml
@@ -44,7 +44,6 @@ tower_governor = { workspace = true }
 tracing = { workspace = true }
 tracing-subscriber = { workspace = true, features = ["env-filter"] }
 utoipa = { workspace = true }
-utoipa-axum = { workspace = true }
 utoipa-swagger-ui = { workspace = true }
 uuid = { workspace = true, features = ["v4"] }
 validator = { workspace = true }
diff --git a/i18n-demo/Cargo.toml b/i18n-demo/Cargo.toml
index 9682a84..749bf51 100644
--- a/i18n-demo/Cargo.toml
+++ b/i18n-demo/Cargo.toml
@@ -31,10 +31,9 @@ serde_json = { workspace = true }
 uuid = { workspace = true, features = ["v4"] }
 tokio = { workspace = true }
 tokio-util = { workspace = true }
-tower-http = { workspace = true, features = ["trace", "fs"] }
+tower-http = { workspace = true, optional = true, features = ["trace", "fs"] }
 tracing = { workspace = true }
-tracing-subscriber = { workspace = true, features = ["env-filter"] }
-leptos-utils = { workspace = true }
+tracing-subscriber = { workspace = true, optional = true, features = ["env-filter"] }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 wasm-bindgen = { workspace = true }
@@ -46,7 +45,7 @@ proc-macro2 = "1"
 
 [features]
 default = []
-ssr = ["dep:leptos_axum", "leptos/ssr", "leptos_i18n/ssr"]
+ssr = ["dep:leptos_axum", "dep:tower-http", "dep:tracing-subscriber", "leptos/ssr", "leptos_i18n/ssr"]
 hydrate = ["leptos/hydrate", "leptos_i18n/hydrate"]
 csr = ["leptos/csr", "leptos_i18n/csr"]
 
diff --git a/live-search/Cargo.toml b/live-search/Cargo.toml
index 4730440..472adcc 100644
--- a/live-search/Cargo.toml
+++ b/live-search/Cargo.toml
@@ -56,11 +56,10 @@ tracing = { workspace = true }
 tracing-subscriber = { workspace = true, features = ["env-filter"] }
 tower-http = { workspace = true, features = ["trace", "fs"] }
 thiserror = { workspace = true }
-axum-prometheus = { workspace = true }
+axum-prometheus = { workspace = true, optional = true }
 moka = { workspace = true }
 base64 = { workspace = true }
 rwf-config = { path = "../crates/config" }
-leptos-utils = { workspace = true }
 # OTel stack — gated behind `otel` feature.
 opentelemetry = { workspace = true, optional = true }
 opentelemetry_sdk = { workspace = true, optional = true }
@@ -81,7 +80,7 @@ rwf-domain = { workspace = true }
 
 [features]
 default = []
-ssr = ["dep:leptos_axum", "leptos/ssr", "leptos-use/ssr"]
+ssr = ["dep:leptos_axum", "dep:axum-prometheus", "leptos/ssr", "leptos-use/ssr"]
 hydrate = ["leptos/hydrate"]
 test-seams = []
 otel = [
diff --git a/live-search/src/app.rs b/live-search/src/app.rs
index f9c5816..8a45bd8 100644
--- a/live-search/src/app.rs
+++ b/live-search/src/app.rs
@@ -176,7 +176,9 @@ fn result_row_renderer(
 
     view! {
         <tr class=class data-testid="result-item" on:click=move |ev| on_select.run(ev)>
-            <td><a href=url.clone()>{title}</a></td>
+            <td>
+                <a href=url.clone()>{title}</a>
+            </td>
             <td>{snippet}</td>
             <td>{url}</td>
         </tr>

From 9875f3fe449d1dabf39b81a809da53e5f557b722 Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 14:54:21 +0200
Subject: [PATCH 15/17] chore: refresh lockfile after dependency cleanup

---
 Cargo.lock | 22 ----------------------
 1 file changed, 22 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index c2910cf..ba2ae88 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1786,7 +1786,6 @@ dependencies = [
  "tracing-opentelemetry",
  "tracing-subscriber",
  "utoipa",
- "utoipa-axum",
  "utoipa-swagger-ui",
  "uuid",
  "validator",
@@ -2301,7 +2300,6 @@ dependencies = [
  "console_error_panic_hook",
  "futures",
  "leptos",
- "leptos-utils",
  "leptos_axum",
  "leptos_i18n",
  "leptos_i18n_build",
@@ -3625,7 +3623,6 @@ dependencies = [
  "leptos",
  "leptos-struct-table",
  "leptos-use 0.19.2",
- "leptos-utils",
  "leptos_axum",
  "leptos_meta",
  "leptos_router",
@@ -4219,12 +4216,6 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
 
-[[package]]
-name = "pastey"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2ee67f1008b1ba2321834326597b8e186293b049a023cdef258527550b9935b4"
-
 [[package]]
 name = "pathdiff"
 version = "0.2.3"
@@ -6880,19 +6871,6 @@ dependencies = [
  "utoipa-gen",
 ]
 
-[[package]]
-name = "utoipa-axum"
-version = "0.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "865319162dc3d0032e1e40ed11bd49d5b78e8ef576740589fd6823e2e9977423"
-dependencies = [
- "axum",
- "pastey",
- "tower-layer",
- "tower-service",
- "utoipa",
-]
-
 [[package]]
 name = "utoipa-gen"
 version = "6.0.1"

From ef99447089b934d6ba0d63d0ccfb14278bac827a Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 15:09:42 +0200
Subject: [PATCH 16/17] fix: align feature-gated dependencies with strict
 manifest lints

---
 Cargo.lock             | 1 -
 e2e-tests/Cargo.toml   | 4 ----
 live-search/Cargo.toml | 3 ++-
 3 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ba2ae88..5a62934 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1389,7 +1389,6 @@ dependencies = [
  "gateway-example",
  "insta",
  "leptos",
- "leptos-utils",
  "leptos_axum",
  "live-search",
  "opentelemetry",
diff --git a/e2e-tests/Cargo.toml b/e2e-tests/Cargo.toml
index 13f9953..5088483 100644
--- a/e2e-tests/Cargo.toml
+++ b/e2e-tests/Cargo.toml
@@ -86,10 +86,6 @@ rwf-domain = { workspace = true }
 
 # Import the real SearchResult type and SSR modules for in-process server
 live-search = { path = "../live-search", features = ["ssr", "test-seams"] }
-# Shared Leptos axum helpers (doubled-prefix server-fn probe) for in-process
-# test launchers
-leptos-utils = { workspace = true }
-
 # Gateway example for in-process HTTP tests
 gateway-example = { path = "../gateway" }
 
diff --git a/live-search/Cargo.toml b/live-search/Cargo.toml
index 472adcc..3589b01 100644
--- a/live-search/Cargo.toml
+++ b/live-search/Cargo.toml
@@ -80,10 +80,11 @@ rwf-domain = { workspace = true }
 
 [features]
 default = []
-ssr = ["dep:leptos_axum", "dep:axum-prometheus", "leptos/ssr", "leptos-use/ssr"]
+ssr = ["dep:leptos_axum", "leptos/ssr", "leptos-use/ssr"]
 hydrate = ["leptos/hydrate"]
 test-seams = []
 otel = [
+    "dep:axum-prometheus",
     "dep:opentelemetry",
     "dep:opentelemetry_sdk",
     "dep:opentelemetry-otlp",

From fcee681dde12c9faf868512eb1b76a4c16d9e877 Mon Sep 17 00:00:00 2001
From: codeandsolder-git-wrangler
 <codeandsolder-git-wrangler@users.noreply.github.com>
Date: Tue, 29 Sep 2026 15:29:13 +0200
Subject: [PATCH 17/17] fix: patch transitive Rust future incompatibilities

---
 Cargo.lock                                    |   4 -
 Cargo.toml                                    |  13 +-
 third-party/README.md                         |  29 +
 third-party/manyhow/.gitignore                |   2 +
 third-party/manyhow/Cargo.toml                | 114 +++
 third-party/manyhow/Cargo.toml.orig           |  55 ++
 third-party/manyhow/LICENSE-APACHE            | 201 +++++
 third-party/manyhow/LICENSE-MIT               |  21 +
 third-party/manyhow/README.md                 | 122 +++
 third-party/manyhow/rustfmt.toml              |  15 +
 third-party/manyhow/src/error.rs              | 515 +++++++++++
 third-party/manyhow/src/lib.rs                | 850 ++++++++++++++++++
 third-party/manyhow/src/macro_rules.rs        | 323 +++++++
 third-party/manyhow/src/parse_to_tokens.rs    | 172 ++++
 third-party/manyhow/src/span_ranged.rs        | 208 +++++
 third-party/proc-macro-error2/.gitignore      |   4 +
 third-party/proc-macro-error2/CHANGELOG.md    | 180 ++++
 third-party/proc-macro-error2/Cargo.toml      |  91 ++
 third-party/proc-macro-error2/Cargo.toml.orig |  41 +
 third-party/proc-macro-error2/LICENSE-APACHE  | 201 +++++
 third-party/proc-macro-error2/LICENSE-MIT     |  21 +
 third-party/proc-macro-error2/README.md       | 250 ++++++
 .../proc-macro-error2/src/diagnostic.rs       | 360 ++++++++
 third-party/proc-macro-error2/src/dummy.rs    | 151 ++++
 .../proc-macro-error2/src/imp/delegate.rs     |  68 ++
 .../proc-macro-error2/src/imp/fallback.rs     |  30 +
 third-party/proc-macro-error2/src/lib.rs      | 565 ++++++++++++
 third-party/proc-macro-error2/src/macros.rs   | 288 ++++++
 third-party/proc-macro-error2/src/sealed.rs   |   3 +
 29 files changed, 4887 insertions(+), 10 deletions(-)
 create mode 100644 third-party/README.md
 create mode 100644 third-party/manyhow/.gitignore
 create mode 100644 third-party/manyhow/Cargo.toml
 create mode 100644 third-party/manyhow/Cargo.toml.orig
 create mode 100644 third-party/manyhow/LICENSE-APACHE
 create mode 100644 third-party/manyhow/LICENSE-MIT
 create mode 100644 third-party/manyhow/README.md
 create mode 100644 third-party/manyhow/rustfmt.toml
 create mode 100644 third-party/manyhow/src/error.rs
 create mode 100644 third-party/manyhow/src/lib.rs
 create mode 100644 third-party/manyhow/src/macro_rules.rs
 create mode 100644 third-party/manyhow/src/parse_to_tokens.rs
 create mode 100644 third-party/manyhow/src/span_ranged.rs
 create mode 100644 third-party/proc-macro-error2/.gitignore
 create mode 100644 third-party/proc-macro-error2/CHANGELOG.md
 create mode 100644 third-party/proc-macro-error2/Cargo.toml
 create mode 100644 third-party/proc-macro-error2/Cargo.toml.orig
 create mode 100644 third-party/proc-macro-error2/LICENSE-APACHE
 create mode 100644 third-party/proc-macro-error2/LICENSE-MIT
 create mode 100644 third-party/proc-macro-error2/README.md
 create mode 100644 third-party/proc-macro-error2/src/diagnostic.rs
 create mode 100644 third-party/proc-macro-error2/src/dummy.rs
 create mode 100644 third-party/proc-macro-error2/src/imp/delegate.rs
 create mode 100644 third-party/proc-macro-error2/src/imp/fallback.rs
 create mode 100644 third-party/proc-macro-error2/src/lib.rs
 create mode 100644 third-party/proc-macro-error2/src/macros.rs
 create mode 100644 third-party/proc-macro-error2/src/sealed.rs

diff --git a/Cargo.lock b/Cargo.lock
index 5a62934..e988d78 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3685,8 +3685,6 @@ checksum = "4050469837a6ff301cd14c1f8f24f88549e6d548f24f64e2148eb0f72cebc51f"
 [[package]]
 name = "manyhow"
 version = "0.11.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b33efb3ca6d3b07393750d4030418d594ab1139cee518f0dc88db70fec873587"
 dependencies = [
  "manyhow-macros",
  "proc-macro2",
@@ -4382,8 +4380,6 @@ dependencies = [
 [[package]]
 name = "proc-macro-error2"
 version = "2.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "11ec05c52be0a07b08061f7dd003e7d7092e0472bc731b4af7bb1ef876109802"
 dependencies = [
  "proc-macro-error-attr2",
  "proc-macro2",
diff --git a/Cargo.toml b/Cargo.toml
index 3dd4b76..f986ed0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,13 @@
 [workspace]
 resolver = "3"
 members = ["crates/config", "crates/domain", "crates/leptos-utils", "gateway", "live-search", "i18n-demo", "e2e-tests"]
+exclude = ["third-party/manyhow", "third-party/proc-macro-error2"]
+
+[patch.crates-io]
+# Temporary source-compatible fixes for dependencies currently used by Leptos.
+# Remove each patch once crates.io/upstream contains the corresponding fix.
+manyhow = { path = "third-party/manyhow" }
+proc-macro-error2 = { path = "third-party/proc-macro-error2" }
 
 [workspace.package]
 version = "0.1.0"
@@ -51,7 +58,6 @@ leptos-use = "0.19"
 leptos-struct-table = "0.19"
 lepticons = "0.13"
 utoipa = "6"
-utoipa-axum = "0.3"
 # `axum` enables the SwaggerUi router builder; `vendored` bundles Swagger UI assets so Docker builds don't need network.
 utoipa-swagger-ui = { version = "10", features = ["axum", "vendored"] }
 opentelemetry = "0.32"
@@ -76,11 +82,6 @@ config = { version = "0.15", default-features = false, features = ["toml"] }
 # Shared domain types (no framework dependencies).
 rwf-domain = { path = "crates/domain" }
 
-# Deprecated compatibility shim around `leptos_axum::handle_server_fns`.
-# New code should call leptos_axum directly; this remains only for source
-# compatibility until downstream users have migrated.
-leptos-utils = { path = "crates/leptos-utils" }
-
 [workspace.lints.rust]
 unsafe_code = "deny"
 rust_2024_compatibility = { level = "deny", priority = -1 }
diff --git a/third-party/README.md b/third-party/README.md
new file mode 100644
index 0000000..9c285ac
--- /dev/null
+++ b/third-party/README.md
@@ -0,0 +1,29 @@
+# Temporary compatibility patches
+
+These crates are exact copies of the crates.io releases selected by `Cargo.lock`,
+with narrowly scoped source-compatible fixes for Rust future-incompatibility
+warnings. They are wired through the root `[patch.crates-io]` table and are
+excluded from workspace membership.
+
+## manyhow 0.11.4
+
+Upstream crate: `manyhow 0.11.4`.
+
+Patch: remove the trailing semicolon from each `bail!` expansion. The macro
+still expands to the same early `return Err(...)`, but callers can use it in
+expression position without triggering Rust issue #79813
+(`semicolon_in_expressions_from_macros`).
+
+This removes the future-incompatibility warnings currently attributed to
+`attribute-derive-macro 0.10.5`.
+
+## proc-macro-error2 2.0.1
+
+Upstream crate: `proc-macro-error2 2.0.1`.
+
+Patch: make the crate's `extern crate proc_macro` public because its hidden
+`__export` module publicly re-exports `proc_macro`. This is the compiler's
+suggested source-compatible fix for Rust issue #127909 / E0365.
+
+`proc-macro-error2` is unmaintained; prefer removing this patch when the
+upstream dependency chain migrates to a maintained replacement.
diff --git a/third-party/manyhow/.gitignore b/third-party/manyhow/.gitignore
new file mode 100644
index 0000000..a9d37c5
--- /dev/null
+++ b/third-party/manyhow/.gitignore
@@ -0,0 +1,2 @@
+target
+Cargo.lock
diff --git a/third-party/manyhow/Cargo.toml b/third-party/manyhow/Cargo.toml
new file mode 100644
index 0000000..5909456
--- /dev/null
+++ b/third-party/manyhow/Cargo.toml
@@ -0,0 +1,114 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2021"
+name = "manyhow"
+version = "0.11.4"
+build = false
+autobins = false
+autoexamples = false
+autotests = false
+autobenches = false
+description = "proc macro error handling à la anyhow x proc-macro-error"
+documentation = "https://docs.rs/manyhow"
+readme = "README.md"
+keywords = [
+    "proc-macro",
+    "error",
+    "error-handling",
+]
+categories = [
+    "development-tools::procedural-macro-helpers",
+    "rust-patterns",
+]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/ModProg/manyhow"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = [
+    "--cfg",
+    "docsrs",
+]
+
+[package.metadata.release]
+shared-version = true
+
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+replace = """
+<!-- ## [Unreleased] -->
+## [{{version}}] - {{date}}"""
+search = '## \[Unreleased\]'
+
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+replace = """
+[unreleased]: $1/{{tag_name}}...HEAD
+[{{version}}]: $1/$2...{{tag_name}}"""
+search = '\[unreleased\]: (.*)/(v.*)\.\.\.HEAD'
+
+[lib]
+name = "manyhow"
+path = "src/lib.rs"
+
+[dependencies.darling_core]
+version = "0.20.1"
+optional = true
+
+[dependencies.macros]
+version = "0.11.4"
+optional = true
+package = "manyhow-macros"
+
+[dependencies.proc-macro2]
+version = "1.0.60"
+
+[dependencies.quote]
+version = "1"
+
+[dependencies.syn1]
+version = "1"
+features = ["printing"]
+optional = true
+default-features = false
+package = "syn"
+
+[dependencies.syn2]
+version = "2"
+features = [
+    "printing",
+    "parsing",
+]
+optional = true
+default-features = false
+package = "syn"
+
+[dev-dependencies.proc-macro-utils]
+version = "0.8.0"
+
+[dev-dependencies.proc-macro2]
+version = "1"
+features = ["span-locations"]
+
+[dev-dependencies.syn2]
+version = "2"
+features = ["full"]
+package = "syn"
+
+[features]
+darling = ["darling_core"]
+default = [
+    "syn",
+    "macros",
+]
+syn = ["syn2"]
diff --git a/third-party/manyhow/Cargo.toml.orig b/third-party/manyhow/Cargo.toml.orig
new file mode 100644
index 0000000..2f5c8bc
--- /dev/null
+++ b/third-party/manyhow/Cargo.toml.orig
@@ -0,0 +1,55 @@
+[package]
+name = "manyhow"
+version = "0.11.4"
+edition = "2021"
+categories = ["development-tools::procedural-macro-helpers", "rust-patterns"]
+description = "proc macro error handling à la anyhow x proc-macro-error"
+keywords = ["proc-macro", "error", "error-handling"]
+license = "MIT OR Apache-2.0"
+readme = "README.md"
+repository = "https://github.com/ModProg/manyhow"
+documentation = "https://docs.rs/manyhow"
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[workspace]
+members = [ "macros", ".", "examples/macro", "examples/no_macro" ]
+
+[dependencies]
+macros = { package = "manyhow-macros", path = "macros", version = "0.11.4", optional = true}
+proc-macro2 = "1.0.60"
+quote = "1"
+syn1 = { package = "syn", version = "1", default-features = false, optional = true, features = ["printing"] }
+syn2 = { package = "syn", version = "2", default-features = false, optional = true, features = ["printing", "parsing"] }
+darling_core = { version = "0.20.1", optional = true }
+
+[features]
+default = ["syn", "macros"]
+syn = ["syn2"]
+darling = ["darling_core"]
+
+[dev-dependencies]
+proc-macro-utils = "0.8.0"
+proc-macro2 = { version = "1", features = ["span-locations"] }
+syn2 = {package = "syn", version = "2", features = ["full"]}
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[package.metadata.release]
+shared-version = true
+
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+search = '## \[Unreleased\]'
+replace = """
+<!-- ## [Unreleased] -->
+## [{{version}}] - {{date}}\
+"""
+[[package.metadata.release.pre-release-replacements]]
+file = "CHANGELOG.md"
+search = '\[unreleased\]: (.*)/(v.*)\.\.\.HEAD'
+replace = """
+[unreleased]: $1/{{tag_name}}...HEAD
+[{{version}}]: $1/$2...{{tag_name}}\
+"""
diff --git a/third-party/manyhow/LICENSE-APACHE b/third-party/manyhow/LICENSE-APACHE
new file mode 100644
index 0000000..da3ea28
--- /dev/null
+++ b/third-party/manyhow/LICENSE-APACHE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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+   1. Definitions.
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diff --git a/third-party/manyhow/LICENSE-MIT b/third-party/manyhow/LICENSE-MIT
new file mode 100644
index 0000000..7c5aea4
--- /dev/null
+++ b/third-party/manyhow/LICENSE-MIT
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 Roland Fredenhagen
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/third-party/manyhow/README.md b/third-party/manyhow/README.md
new file mode 100644
index 0000000..e9a257b
--- /dev/null
+++ b/third-party/manyhow/README.md
@@ -0,0 +1,122 @@
+# manyhow
+## anyhow for proc macros
+[![CI Status](https://github.com/ModProg/manyhow/actions/workflows/test.yaml/badge.svg)](https://github.com/ModProg/manyhow/actions/workflows/test.yaml)
+[![Crates.io](https://img.shields.io/crates/v/manyhow)](https://crates.io/crates/manyhow)
+[![Docs.rs](https://img.shields.io/crates/v/template?color=informational&label=docs.rs)](https://docs.rs/manyhow)
+[![Documentation for `main`](https://img.shields.io/badge/docs-main-informational)](https://modprog.github.io/manyhow/manyhow/)
+
+Proc **m**acro **anyhow**, a combination of ideas from
+[`anyhow`](https://docs.rs/anyhow) and
+[`proc-macro-error`](https://docs.rs/proc-macro-error) to improve proc macro
+development, especially focused on the error handling.
+
+## Motivation
+Error handling in proc-macros is unideal, as the top level functions of proc
+macros can only return `TokenStreams` both in success and failure case. This
+means that I often write code like this, moving the actual implementation in
+a separate function to be able to use the ergonomic rust error handling with
+e.g., `?`.
+```rust
+use proc_macro2::TokenStream as TokenStream2;
+
+#[proc_macro]
+pub fn my_macro(input: TokenStream) -> TokenStream {
+    match actual_implementation(input.into()) {
+        Ok(output) => output,
+        Err(error) => error.into_compile_error(),
+    }
+    .into()
+}
+
+fn actual_implementation(input: TokenStream2) -> syn::Result<TokenStream2> {
+    // ..
+}
+```
+
+## Using the `#[manyhow]` macro
+To activate the error handling, just add `#[manyhow]` above any
+proc macro implementation, reducing the above example to:
+
+```rust
+use manyhow::manyhow;
+use proc_macro2::TokenStream as TokenStream2;
+
+#[manyhow]
+#[proc_macro]
+fn my_macro(input: TokenStream2) -> syn::Result<TokenStream2> {
+    // ..
+}
+```
+
+See [Without macros](#without-macros) to see what this expands to under the
+hood.
+
+A proc macro function marked as `#[manyhow]` can take and return any
+`TokenStream` and can also return `Result<TokenStream,
+E>` where `E` implements `ToTokensError`. As additional parameters a
+[dummy](#dummy-mut-tokenstream) and/or [emitter](#emitter-mut-emitter) can
+be specified.
+
+The `manyhow` attribute takes one optional flag when used for `proc_macro`
+and `proc_macro_attribute`. `#[manyhow(input_as_dummy)]` will take the input
+of a function like `proc_macro` to initialize the [dummy `&mut
+TokenStream`](#dummy-mut-tokenstream) while `#[manyhow(item_as_dummy)]` on
+`proc_macro_attribute` will initialize the dummy with the annotated item.
+
+## Without macros
+`manyhow` can be used without proc macros, and they can be disabled by
+adding `manyhow` with `default-features=false`.
+
+The usage is more or less the same, though with some added boilerplate from
+needing to invoke one of `function`, `attribute` or `derive`
+directly.
+
+While the examples use closures, functions can be passed in as well. The
+above example would then change to:
+```rust
+use proc_macro2::TokenStream as TokenStream2;
+
+#[proc_macro]
+pub fn my_macro(input: TokenStream) -> TokenStream {
+    manyhow::function(
+        input,
+        false,
+        |input: TokenStream2| -> syn::Result<TokenStream2> {
+            // ..
+        },
+    )
+}
+```
+[`Emitter`](#emitter-mut-emitter) and [dummy
+`TokenStream`](#dummy-mut-tokenstream) can also be used. `function` and
+`attribute` take an additional boolean parameter controlling whether the
+input/item will be used as initial dummy.
+
+## `emitter: &mut Emitter`
+`MacroHandler`s (the trait defining what closures/functions can be used
+with `manyhow`) can take a mutable reference to an `Emitter`. This
+allows to collect errors, but not fail immediately.
+
+`Emitter::into_result` can be used to return if an `Emitter` contains
+any values.
+
+```rust
+use manyhow::{manyhow, Emitter, ErrorMessage};
+use proc_macro2::TokenStream as TokenStream2;
+
+#[manyhow]
+#[proc_macro]
+fn my_macro(input: TokenStream2, emitter: &mut Emitter) -> manyhow::Result<TokenStream2> {
+    // ..
+    emitter.emit(ErrorMessage::call_site("A fun error!"));
+    emitter.into_result()?;
+    // ..
+}
+```
+
+## `dummy: &mut TokenStream`
+`MacroHandler`s also take a mutable reference to a `TokenStream`, to
+enable emitting some dummy code to be used in case the macro errors.
+
+This allows either appending tokens e.g., with `ToTokens::to_tokens` or
+directly setting the dummy code e.g., `*dummy = quote!{some tokens}`.
diff --git a/third-party/manyhow/rustfmt.toml b/third-party/manyhow/rustfmt.toml
new file mode 100644
index 0000000..c7cf2dc
--- /dev/null
+++ b/third-party/manyhow/rustfmt.toml
@@ -0,0 +1,15 @@
+condense_wildcard_suffixes = true
+format_code_in_doc_comments = true
+format_macro_matchers = true
+format_strings = true
+hex_literal_case = "Upper"
+imports_granularity = "Module"
+normalize_comments = true
+normalize_doc_attributes = true
+overflow_delimited_expr = true
+reorder_impl_items = true
+group_imports = "StdExternalCrate"
+unstable_features = true
+use_field_init_shorthand = true
+version = "Two"
+wrap_comments = true
diff --git a/third-party/manyhow/src/error.rs b/third-party/manyhow/src/error.rs
new file mode 100644
index 0000000..0350682
--- /dev/null
+++ b/third-party/manyhow/src/error.rs
@@ -0,0 +1,515 @@
+#![allow(clippy::missing_errors_doc)]
+use std::convert::Infallible;
+use std::fmt::{Debug, Display};
+use std::mem;
+use std::ops::{Add, AddAssign, Range};
+
+#[cfg(feature = "darling")]
+use darling_core::Error as DarlingError;
+use proc_macro2::{Span, TokenStream};
+use quote::{quote_spanned, ToTokens};
+#[cfg(feature = "syn1")]
+use syn1::Error as Syn1Error;
+#[cfg(feature = "syn2")]
+use syn2::Error as Syn2Error;
+
+#[cfg(doc)]
+use crate::MacroOutput;
+use crate::{to_tokens_span_range, SpanRanged};
+
+/// An alias for [`Result`](std::result::Result) suited for use with this crate
+pub type Result<T = TokenStream, E = Error> = std::result::Result<T, E>;
+
+/// Error that does not expand to any [`compile_error!`] and therefor does not
+/// cause compilation to fail.
+#[derive(Debug)]
+pub struct SilentError;
+
+/// This crates Error type
+#[derive(Debug)]
+#[must_use]
+pub struct Error(Vec<Box<dyn ToTokensError>>);
+#[cfg(feature = "syn1")]
+impl From<Syn1Error> for Error {
+    fn from(error: Syn1Error) -> Self {
+        Self::from(error)
+    }
+}
+#[cfg(feature = "syn2")]
+impl From<Syn2Error> for Error {
+    fn from(error: Syn2Error) -> Self {
+        Self::from(error)
+    }
+}
+#[cfg(feature = "darling")]
+impl From<DarlingError> for Error {
+    fn from(error: DarlingError) -> Self {
+        Self::from(error)
+    }
+}
+impl From<ErrorMessage> for Error {
+    fn from(error: ErrorMessage) -> Self {
+        Self::from(error)
+    }
+}
+impl From<SilentError> for Error {
+    fn from(_: SilentError) -> Self {
+        Self(Vec::new())
+    }
+}
+
+impl<T: ToTokensError + 'static> Add<T> for Error {
+    type Output = Error;
+
+    fn add(self, rhs: T) -> Self::Output {
+        self.join(rhs)
+    }
+}
+
+impl<T: ToTokensError + 'static> AddAssign<T> for Error {
+    fn add_assign(&mut self, rhs: T) {
+        self.push(rhs);
+    }
+}
+
+impl Error {
+    /// Mimics [`From<impl ToTokensError> for Error`](From) implementation to
+    /// not conflict std's `From<T> for T`
+    pub fn from(error: impl ToTokensError + 'static) -> Self {
+        Self(vec![Box::new(error)])
+    }
+
+    /// Pushes an additional `Error`
+    ///
+    /// Alternatively errors can also be "added":
+    ///
+    /// ```
+    /// use manyhow::{Error, error_message};
+    /// let mut error = Error::from(error_message!("Hello Rust!"));
+    /// error += error_message!("Hello 🦀!");
+    /// # use manyhow::ToTokensError;
+    /// # proc_macro_utils::assert_tokens!(error.into_token_stream(),
+    /// #     { ::core::compile_error!{"Hello Rust!"} ::core::compile_error!{"Hello 🦀!"} });
+    /// ```
+    pub fn push(&mut self, error: impl ToTokensError + 'static) {
+        self.0.push(Box::new(error));
+    }
+}
+
+impl<I: ToTokensError + 'static> Extend<I> for Error {
+    fn extend<T: IntoIterator<Item = I>>(&mut self, iter: T) {
+        self.0.extend(
+            iter.into_iter()
+                .map(|i| Box::new(i) as Box<dyn ToTokensError>),
+        );
+    }
+}
+
+/// A single error message
+///
+/// Can take additional attachments like [`help`](Self::help) or
+/// [`note`](Self::note).
+///
+/// Implements `ToTokensError` and can therefore be used with
+/// [`MacroOutput`]s.
+#[derive(Debug)]
+#[must_use]
+pub struct ErrorMessage {
+    span: Range<Span>,
+    msg: String,
+    attachments: Vec<(&'static str, String)>,
+}
+impl Display for ErrorMessage {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.msg.trim_end())?;
+        if !self.attachments.is_empty() {
+            write!(f, "\n\n")?;
+        }
+        for (label, attachment) in &self.attachments {
+            let mut attachment = attachment.lines();
+            writeln!(
+                f,
+                "  = {label}: {}",
+                attachment.next().expect("should return at least one line")
+            )?;
+            for line in attachment {
+                // `labels` should always be one char per cell
+                writeln!(f, "    {1:2$}  {}", line, "", label.len())?;
+            }
+        }
+        Ok(())
+    }
+}
+impl ToTokensError for ErrorMessage {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let msg = self.to_string();
+        let msg = quote_spanned!(self.span.end => {#msg});
+        quote_spanned! {self.span.start =>
+            ::core::compile_error! #msg
+        }
+        .to_tokens(tokens);
+    }
+}
+
+#[cfg(feature = "syn1")]
+impl From<ErrorMessage> for Syn1Error {
+    fn from(value: ErrorMessage) -> Self {
+        Self::new_spanned(value.to_token_stream(), value)
+    }
+}
+#[cfg(feature = "syn2")]
+impl From<ErrorMessage> for Syn2Error {
+    fn from(value: ErrorMessage) -> Self {
+        Self::new_spanned(value.to_token_stream(), value)
+    }
+}
+
+impl<T: ToTokensError + 'static> Add<T> for ErrorMessage {
+    type Output = Error;
+
+    fn add(self, rhs: T) -> Self::Output {
+        self.join(rhs)
+    }
+}
+
+impl ErrorMessage {
+    /// Creates a new error message at the specified span
+    ///
+    /// This function takes a [`SpanRanged`] meaning you can also pass a
+    /// [`Range`](Range)[`<Span>`](Span) (i.e. `first..last`) for better error
+    /// messages on multi token values, for details see
+    /// [SpanRanged#motivation](SpanRanged#motivation)
+    ///
+    /// If your type implements [`ToTokens`] use [`ErrorMessage::spanned`]
+    /// instead.
+    pub fn new(span: impl SpanRanged, msg: impl Display) -> Self {
+        Self {
+            span: span.span_range(),
+            msg: msg.to_string(),
+            attachments: Vec::new(),
+        }
+    }
+
+    /// Creates an error message pointing to the complete token stream `tokens`
+    /// expands to
+    pub fn spanned(tokens: impl ToTokens, msg: impl Display) -> Self {
+        Self {
+            span: to_tokens_span_range(tokens),
+            msg: msg.to_string(),
+            attachments: Vec::new(),
+        }
+    }
+
+    /// Creates a new error message at [`Span::call_site`] prefer
+    /// [`ErrorMessage::new`] or [`ErrorMessage::spanned`] with the correct span
+    /// for a more helpful output.
+    pub fn call_site(msg: impl Display) -> Self {
+        Self::new(Span::call_site(), msg)
+    }
+
+    /// Attaches an additional message to `self` reusing the same
+    /// span, and the specified `label`.
+    pub fn attachment(mut self, label: &'static str, msg: impl Display) -> Self {
+        self.attachments.push((label, msg.to_string()));
+        self
+    }
+
+    /// Attaches a new `error` message to `self` reusing the same span
+    pub fn error(self, msg: impl Display) -> Self {
+        self.attachment("error", msg)
+    }
+
+    /// Attaches a new `warning` message to `self` reusing the same span
+    pub fn warning(self, msg: impl Display) -> Self {
+        self.attachment("warning", msg)
+    }
+
+    /// Attaches a new `note` message to `self` reusing the same span
+    pub fn note(self, msg: impl Display) -> Self {
+        self.attachment("note", msg)
+    }
+
+    /// Attaches a new `help` message to `self` reusing the same span
+    pub fn help(self, msg: impl Display) -> Self {
+        self.attachment("help", msg)
+    }
+}
+
+/// Exposes [`ErrorMessage::attachment`] as a trait to allow
+/// [`ResultExt::attachment`].
+pub trait Attachment: Sized {
+    /// Attaches an additional message to `self` reusing the same
+    /// span, and the specified `label`.
+    #[must_use]
+    fn attachment(self, label: &'static str, msg: impl Display) -> Self;
+}
+
+impl Attachment for ErrorMessage {
+    fn attachment(mut self, label: &'static str, msg: impl Display) -> Self {
+        self.attachments.push((label, msg.to_string()));
+        self
+    }
+}
+
+/// Allows emitting errors without returning.
+#[derive(Default, Debug)]
+pub struct Emitter(Vec<Box<dyn ToTokensError>>);
+
+impl<T: ToTokensError + 'static> AddAssign<T> for Emitter {
+    fn add_assign(&mut self, rhs: T) {
+        self.emit(rhs);
+    }
+}
+
+impl Emitter {
+    /// Creates an `Emitter`, this can be used to collect errors than can later
+    /// be converted with [`Emitter::into_result()`].
+    #[must_use]
+    pub fn new() -> Self {
+        Emitter(Vec::new())
+    }
+
+    pub(crate) fn to_tokens(&self, tokens: &mut TokenStream) {
+        for error in &self.0 {
+            error.to_tokens(tokens);
+        }
+    }
+
+    /// Emits an error
+    ///
+    /// Alternatively errors can also be "added":
+    ///
+    /// ```
+    /// let mut emitter = manyhow::Emitter::new();
+    /// emitter += manyhow::error_message!("Hello World!");
+    /// # use manyhow::ToTokensError;
+    /// # proc_macro_utils::assert_tokens!(emitter.into_result().unwrap_err().into_token_stream(), { ::core::compile_error!{"Hello World!"} });
+    /// ```
+    pub fn emit(&mut self, error: impl ToTokensError + 'static) {
+        self.0.push(Box::new(error));
+    }
+
+    /// Checks if any errors were emitted
+    #[must_use]
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    /// Removes all emitted errors
+    pub fn clear(&mut self) {
+        self.0.clear();
+    }
+
+    /// Returns emitted errors if not [`Self::is_empty`].
+    ///
+    /// If no errors where emitted, returns `Ok(())`.
+    ///
+    /// *Note:* This clears the emitter to avoid returning duplicate errors.
+    pub fn into_result(&mut self) -> Result<(), Error> {
+        if self.is_empty() {
+            Ok(())
+        } else {
+            Err(Error(mem::take(&mut self.0)))
+        }
+    }
+}
+
+impl<I: ToTokensError + 'static> Extend<I> for Emitter {
+    fn extend<T: IntoIterator<Item = I>>(&mut self, iter: T) {
+        self.0.extend(
+            iter.into_iter()
+                .map(|i| Box::new(i) as Box<dyn ToTokensError>),
+        );
+    }
+}
+
+/// Error that can be converted to a [`TokenStream`] required to be used with
+/// [`MacroOutput`]
+///
+/// This trait is equivalent to [`ToTokens`].
+pub trait ToTokensError: Debug {
+    /// Equivalent to [`ToTokens::to_tokens`]
+    fn to_tokens(&self, tokens: &mut TokenStream);
+    /// Equivalent to [`ToTokens::to_token_stream`]
+    fn to_token_stream(&self) -> TokenStream {
+        let mut tokens = TokenStream::new();
+        self.to_tokens(&mut tokens);
+        tokens
+    }
+    /// Equivalent to [`ToTokens::into_token_stream`]
+    fn into_token_stream(self) -> TokenStream
+    where
+        Self: Sized,
+    {
+        self.to_token_stream()
+    }
+}
+
+/// Allows to call `.join(..)` on any `impl ToTokensError`
+pub trait JoinToTokensError {
+    /// Joins two `Error`s
+    ///
+    /// ```
+    /// use manyhow::error_message;
+    /// # use crate::manyhow::JoinToTokensError;
+    ///
+    /// error_message!("test").join(error_message!("another"));
+    /// ```
+    ///
+    /// Some errors like [`manyhow::Error`] and [`manyhow::ErrorMessage`] can
+    /// also be "added":
+    ///
+    /// ```
+    /// # use manyhow::ToTokensError;
+    /// use manyhow::{error_message, Error};
+    /// # proc_macro_utils::assert_tokens!((
+    /// error_message!("Hello Rust!") + error_message!("Hello 🦀!")
+    /// # ).into_token_stream(), { ::core::compile_error!{"Hello Rust!"} ::core::compile_error!{"Hello 🦀!"} });
+    /// # proc_macro_utils::assert_tokens!((
+    /// Error::from(error_message!("Hello Rust!")) + error_message!("Hello 🦀!")
+    /// # ).into_token_stream(), { ::core::compile_error!{"Hello Rust!"} ::core::compile_error!{"Hello 🦀!"} });
+    /// ```
+    fn join(self, error: impl ToTokensError + 'static) -> Error;
+}
+
+impl<T: Sized + ToTokensError + 'static> JoinToTokensError for T {
+    fn join(self, error: impl ToTokensError + 'static) -> Error {
+        let mut this = Error::from(self);
+        this.push(error);
+        this
+    }
+}
+
+impl ToTokensError for Infallible {
+    fn to_tokens(&self, _: &mut TokenStream) {
+        unreachable!()
+    }
+}
+#[cfg(feature = "syn1")]
+impl ToTokensError for Syn1Error {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        self.to_compile_error().to_tokens(tokens);
+    }
+}
+#[cfg(feature = "syn")]
+impl ToTokensError for Syn2Error {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        self.to_compile_error().to_tokens(tokens);
+    }
+}
+#[cfg(feature = "darling")]
+impl ToTokensError for DarlingError {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        self.clone().write_errors().to_tokens(tokens);
+    }
+}
+impl ToTokensError for Error {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        for error in &self.0 {
+            error.to_tokens(tokens);
+        }
+    }
+}
+impl ToTokensError for SilentError {
+    fn to_tokens(&self, _: &mut TokenStream) {}
+}
+
+/// Some utilities on [`Result<T, impl ToTokensError>`](ToTokensError)
+pub trait ResultExt<T, E>: Sized {
+    /// If self is error, attaches another error
+    fn context(self, error: impl ToTokensError + 'static) -> Result<T, Error> {
+        self.context_with(|| error)
+    }
+
+    /// If self is error, attaches another error, closure is only executed if
+    /// the `Result` is `Err`
+    fn context_with<C: ToTokensError + 'static>(
+        self,
+        error: impl FnOnce() -> C,
+    ) -> Result<T, Error>;
+    /// If self is error, extend error message
+    ///
+    /// Only works if `E` implements [`Attachment`] which is the case for
+    /// [`ErrorMessage`]
+    #[must_use]
+    fn attachment(self, label: &'static str, msg: impl Display) -> Self
+    where
+        E: Attachment;
+
+    /// Attaches a new `error` message to `self` reusing the same span
+    #[must_use]
+    fn error(self, msg: impl Display) -> Self
+    where
+        E: Attachment,
+    {
+        self.attachment("error", msg)
+    }
+
+    /// Attaches a new `warning` message to `self` reusing the same span
+    #[must_use]
+    fn warning(self, msg: impl Display) -> Self
+    where
+        E: Attachment,
+    {
+        self.attachment("warning", msg)
+    }
+
+    /// Attaches a new `note` message to `self` reusing the same span
+    #[must_use]
+    fn note(self, msg: impl Display) -> Self
+    where
+        E: Attachment,
+    {
+        self.attachment("note", msg)
+    }
+
+    /// Attaches a new `help` message to `self` reusing the same span
+    #[must_use]
+    fn help(self, msg: impl Display) -> Self
+    where
+        E: Attachment,
+    {
+        self.attachment("help", msg)
+    }
+}
+
+impl<T, E: ToTokensError + 'static> ResultExt<T, E> for Result<T, E> {
+    fn context_with<C: ToTokensError + 'static>(
+        self,
+        error: impl FnOnce() -> C,
+    ) -> Result<T, Error> {
+        self.map_err(|e| {
+            let mut e = Error::from(e);
+            e.push(error());
+            e
+        })
+    }
+
+    fn attachment(self, label: &'static str, msg: impl Display) -> Result<T, E>
+    where
+        E: Attachment,
+    {
+        self.map_err(|e| e.attachment(label, msg))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use proc_macro_utils::assert_tokens;
+
+    use super::*;
+
+    #[test]
+    fn error_message() {
+        let error_message = ErrorMessage::new(Span::call_site(), "test message")
+            .help("try to call your dog")
+            .note("you could use the banana phone")
+            .warning("be careful")
+            .error("you cannot reach them");
+        assert_tokens! {error_message.to_token_stream(), {
+            ::core::compile_error! {
+                "test message\n\n  = help: try to call your dog\n  = note: you could use the banana phone\n  = warning: be careful\n  = error: you cannot reach them\n"
+            }
+        }}
+    }
+}
diff --git a/third-party/manyhow/src/lib.rs b/third-party/manyhow/src/lib.rs
new file mode 100644
index 0000000..1a66edf
--- /dev/null
+++ b/third-party/manyhow/src/lib.rs
@@ -0,0 +1,850 @@
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![warn(clippy::pedantic, missing_docs)]
+#![allow(clippy::module_name_repetitions)]
+//! Proc **m**acro **anyhow**, a combination of ideas from
+//! [`anyhow`](docs.rs/anyhow) and
+//! [`proc-macro-error`](docs.rs/proc-macro-error) to improve proc macro
+//! development, especially focused on the error handling.
+//!
+//! # Motivation
+//! Error handling in proc-macros is unideal, as the top level functions of
+//! proc-macros can only return `TokenStreams` both in success and failure case.
+//! This means that I often write code like this, moving the actual
+//! implementation in a separate function to be able to use the ergonomic rust
+//! error handling with e.g., `?`.
+//! ```
+//! # use proc_macro2::TokenStream;
+//! # use quote::quote;
+//! # use syn2 as syn;
+//! use proc_macro2::TokenStream as TokenStream2;
+//!
+//! # let _ = quote!{
+//! #[proc_macro]
+//! # };
+//! pub fn my_macro(input: TokenStream) -> TokenStream {
+//!     match actual_implementation(input.into()) {
+//!         Ok(output) => output,
+//!         Err(error) => error.into_compile_error(),
+//!     }
+//!     .into()
+//! }
+//!
+//! fn actual_implementation(input: TokenStream2) -> syn::Result<TokenStream2> {
+//!     // ..
+//! #   Ok(quote!())
+//! }
+//! ```
+//!
+//! # Using the `#[manyhow]` macro
+//! To activate the error handling, just add [`#[manyhow]`](manyhow) above any
+//! proc-macro implementation, reducing the above example to:
+//!
+//! ```
+//! # use quote::quote;
+//! # use syn2 as syn;
+//! use manyhow::manyhow;
+//! use proc_macro2::TokenStream as TokenStream2;
+//!
+//! # let _ = quote!{
+//! #[manyhow]
+//! #[proc_macro]
+//! # };
+//! // You can also merge the two attributes: #[manyhow(proc_macro)]
+//! fn my_macro(input: TokenStream2) -> syn::Result<TokenStream2> {
+//!     // ..
+//! #   Ok(quote!())
+//! }
+//!
+//! // On top of the TokenStreams any type that implements [`Parse`] is supported
+//! # let _ = quote!{
+//! #[manyhow(proc_macro_derive(MyMacro))]
+//! #[proc_macro]
+//! # };
+//! // The output can also be anything that implements `quote::ToTokens`
+//! fn my_derive_macro(input: syn::DeriveInput) -> manyhow::Result<syn::ItemImpl> {
+//!     // ..
+//! #   manyhow::bail!("hello")
+//! }
+//! ```
+//!
+//! See [Without macros](#without-macros) to see what this expands to under the
+//! hood.
+//!
+//! You can also use the `#[manyhow]` attributes on a use statement, useful when
+//! moving your proc-macro implementations in separate modules.
+//!
+//! ```
+//! # use quote::quote;
+//! use manyhow::manyhow;
+//!
+//! mod module {
+//!     # use quote::quote;
+//!     # use syn2 as syn;
+//!     use proc_macro2::TokenStream as TokenStream2;
+//!
+//!     pub fn my_macro(input: TokenStream2) -> syn::Result<TokenStream2> {
+//!         // ..
+//!     #   Ok(quote!())
+//!     }
+//! }
+//!
+//! # let _ = quote!{
+//! #[manyhow]
+//! #[proc_macro]
+//! # };
+//! // You can also merge the two attributes: #[manyhow(proc_macro)]
+//! pub use module::my_macro;
+//! ```
+//!
+//! A proc macro function marked as `#[manyhow]` can take and return any
+//! [`TokenStream`](AnyTokenStream), and can also return `Result<TokenStream,
+//! E>` where `E` implements [`ToTokensError`]. As additional parameters a
+//! [dummy](#dummy-mut-tokenstream) and/or [emitter](#emitter-mut-emitter) can
+//! be specified.
+//!
+//! The `manyhow` attribute takes optional flags to configure its behavior.
+//!
+//! When used for `proc_macro` and `proc_macro_attribute`,
+//! `#[manyhow(input_as_dummy, ...)]` will take the input of a function like
+//! `proc_macro` to initialize the [dummy `&mut TokenStream`](#
+//! dummy-mut-tokenstream) while `#[manyhow(item_as_dummy, ...)]` on
+//! `proc_macro_attribute` will initialize the dummy with the annotated item.
+//!
+//! You can merge the `#[proc_macro*]` attribute inside the manyhow flags e.g.,
+//! `#[manyhow(proc_macro)]` or `#[manyhow(proc_macro_derive(SomeTrait, ...))]`.
+//!
+//! The `#[manyhow(impl_fn, ...)]` flag will put the actual macro implementation
+//! in a separate function. Making it available for e.g., unit testing with
+//! [`proc_macro_utils::assert_expansion!`](https://docs.rs/proc-macro-utils/latest/proc_macro_utils/macro.assert_expansion.html).
+//!
+//! ```ignore
+//! #[manyhow(impl_fn)]
+//! #[proc_macro]
+//! pub fn actual_macro(input: TokenStream2) -> TokenStream2 {
+//!     // ...
+//! }
+//! // would roughly expand to
+//! #[proc_macro]
+//! pub fn actual_macro(input: TokenStream) -> TokenStream {
+//!     actual_macro_impl(input.into()).into()
+//! }
+//! fn actual_macro_impl(input: TokenStream2) -> TokenStream2 {
+//!     // ...
+//! }
+//! ```
+//!
+//! # Without macros
+//! `manyhow` can be used without proc macros, and they can be disabled by
+//! adding `manyhow` with `default-features=false`.
+//!
+//! The usage is more or less the same, though with some added boilerplate from
+//! needing to invoke one of [`function()`] ([`function!`]), [`attribute()`]
+//! ([`attribute!`]) or [`derive()`] ([`derive!`]) directly. For each version
+//! there exists a function and a `macro_rules` macro, while the function only
+//! supports [`proc_macro::TokenStream`] and [`proc_macro2::TokenStream`], the
+//! macro versions also support any type that implements [`Parse`]
+//! and [`ToTokens`] respectively.
+//!
+//! While the examples use closures, functions can be passed in as well. The
+//! above example would then change to:
+//! ```
+//! # use proc_macro2::TokenStream;
+//! # use quote::quote;
+//! # use syn2 as syn;
+//! use proc_macro2::TokenStream as TokenStream2;
+//!
+//! # let _ = quote!{
+//! #[proc_macro]
+//! # };
+//! pub fn my_macro(input: TokenStream) -> TokenStream {
+//! # let tmp = input.clone();
+//! # let output: TokenStream =
+//!     manyhow::function(
+//!         input,
+//!         false,
+//!         |input: TokenStream2| -> syn::Result<TokenStream2> {
+//!             // ..
+//! #           Ok(quote!())
+//!         },
+//!     )
+//! # ;
+//! # let input = tmp;
+//!     // Or
+//!     manyhow::function!(
+//!         input,
+//!         |input: syn::DeriveInput| -> manyhow::Result<syn::ItemImpl> {
+//!             // ..
+//! #           manyhow::bail!("error")
+//!         },
+//!     )
+//! }
+//! ```
+//! [`Emitter`](#emitter-mut-emitter) and [dummy
+//! `TokenStream`](#dummy-mut-tokenstream) can also be used. [`function()`]
+//! ([`function!`]) and [`attribute()`] ([`attribute!`]) take an additional
+//! boolean parameter controlling whether the input/item will be used as initial
+//! dummy.
+//!
+//! # `emitter: &mut Emitter`
+//! [`*MacroHandler`](FunctionMacroHandler)s (the traits defining what
+//! closures/functions can be used with `manyhow`) can take a mutable reference
+//! to an [`Emitter`]. This allows collecting errors, but not fail immediately.
+//!
+//! [`Emitter::into_result`] can be used to return if an [`Emitter`] contains
+//! any values.
+//!
+//! ```
+//! # use quote::quote;
+//! # use syn2 as syn;
+//! use manyhow::{manyhow, Emitter, ErrorMessage};
+//! use proc_macro2::TokenStream as TokenStream2;
+//!
+//! # let _ = quote!{
+//! #[manyhow]
+//! #[proc_macro]
+//! # };
+//! fn my_macro(input: TokenStream2, emitter: &mut Emitter) -> manyhow::Result<TokenStream2> {
+//!     // ..
+//!     emitter.emit(ErrorMessage::call_site("A fun error!"));
+//!     emitter.into_result()?;
+//!     // ..
+//! #   Ok(quote!())
+//! }
+//! ```
+//!
+//! # `dummy: &mut TokenStream`
+//! [`*MacroHandler`](FunctionMacroHandler)s can also take a mutable reference
+//! to a `TokenStream`, to enable emitting some dummy code to be used in case
+//! the macro errors.
+//!
+//! This allows either appending tokens e.g., with [`ToTokens::to_tokens`] or
+//! directly setting the dummy code e.g., `*dummy = quote!{some tokens}`.
+//!
+//! # Crate features
+//!
+//! - `macros` **default** Enables [`#[manyhow]`](macros::manyhow) attribute
+//!   macro.
+//! - `syn`/`syn2` **default** Enables errors for [`syn` 2.x](https://docs.rs/syn/latest/syn/).
+//! - `syn1` Enables errors for [`syn` 1.x](https://docs.rs/syn/1.0.109/syn/index.html).
+//! - `darling` Enables errors for [`darling`](https://docs.rs/darling/latest/index.html).
+
+#[cfg(feature = "macros")]
+pub use macros::manyhow;
+use proc_macro2::TokenStream;
+#[cfg(doc)]
+use {quote::ToTokens, syn2::parse::Parse};
+
+extern crate proc_macro;
+
+#[macro_use]
+mod span_ranged;
+pub use span_ranged::{to_tokens_span_range, SpanRanged};
+#[macro_use]
+mod macro_rules;
+mod error;
+pub use error::*;
+
+mod parse_to_tokens;
+
+#[doc(hidden)]
+pub mod __private {
+    pub use std::prelude::rust_2021::*;
+
+    use proc_macro2::TokenStream;
+    pub use quote;
+
+    pub use crate::span_ranged::*;
+    pub type Dummy = Option<TokenStream>;
+
+    pub use crate::parse_to_tokens::*;
+}
+
+/// Marker trait for [`proc_macro::TokenStream`] and
+/// [`proc_macro2::TokenStream`]
+pub trait AnyTokenStream: Clone + From<TokenStream> + Into<TokenStream> + Default {}
+impl AnyTokenStream for TokenStream {}
+impl AnyTokenStream for proc_macro::TokenStream {}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! __macro_handler {
+    ($name:ident; $($(#attr=$attr:tt)? $n:ident: $input:expr),+; $impl:expr$(; dummy:$dummy:expr)?) => {
+        $crate::__macro_handler! {! $name; $($(#attr=$attr)? $n: $input.clone()),+; $impl $(; $crate::__private::Some($dummy))?}
+    };
+    ($name:ident; $($(#attr=$attr:tt)? $n:ident: $input:expr),+; $impl:expr; dummy) => {
+        $crate::__macro_handler! {! $name; $($(#attr=$attr)? $n: $input),+; $impl; $crate::__private::Dummy::None}
+    };
+    (! $name:ident; $($(#attr=$attr:tt)? $n:ident: $input:expr),+; $impl:expr $(; $dummy:expr)?) => {{
+        use $crate::__private::{ManyhowParse, ManyhowToTokens, ManyhowTry};
+        let implementation = $impl;
+        $(let $n = &$crate::__private::WhatType::new();)+
+        if false {
+            _ = $crate::__private::$name($($n.identify(),)+ $($dummy,)? implementation);
+            unreachable!();
+        } else {
+            match $crate::__private::$name($(
+                {#[allow(unused)]
+                let attr = false;
+                $(let attr = $attr;)?
+                $n.manyhow_parse($input, attr)},
+            )+ $($dummy,)? implementation)
+            {
+                Err(tokens) => tokens.into(),
+                Ok((output, mut tokens, mut dummy)) => {
+                    match (&$crate::__private::WhatType::from(&output)).manyhow_try(output) {
+                        Err(error) => {
+                            dummy.extend(tokens);
+                            tokens = dummy;
+                            (&$crate::__private::WhatType::from(&error)).manyhow_to_tokens(error, &mut tokens);
+                        },
+                        Ok(output) => (&$crate::__private::WhatType::from(&output)).manyhow_to_tokens(output, &mut tokens),
+                    };
+                    tokens.into()
+                }
+            }
+        }
+    }};
+}
+
+/// Handles [`proc_macro_attribute`](https://doc.rust-lang.org/reference/procedural-macros.html#attribute-macros)
+/// implementation
+///
+/// Takes any `TokenStream` for `input` and `item` and returns any
+/// `TokenStream`. If `item_as_dummy = true` the item input will be used as
+/// default dummy code on error. `body` takes a [`AttributeMacroHandler`] with
+/// two `TokenStream` parameters. And an optional [`&mut Emitter`](Emitter) and
+/// a `&mut TokenStream` for storing a dummy output.
+///
+/// ```
+/// # use proc_macro_utils::assert_tokens;
+/// # use quote::{quote, ToTokens};
+/// use manyhow::{attribute, Emitter, Result};
+/// use proc_macro2::TokenStream;
+/// # let input = quote!();
+/// # let item = quote!();
+/// # let output: TokenStream =
+/// attribute(
+///     input,
+///     item,
+///     false,
+///     |input: TokenStream,
+///      item: TokenStream,
+///      dummy: &mut TokenStream,
+///      emitter: &mut Emitter|
+///      -> Result {
+///         // ..
+///         # Ok(quote!())
+///     },
+/// );
+/// ```
+///
+/// *Note:* When `item_as_dummy = true` the `dummy: &mut TokenStream` will be
+/// initialized with `item`. To override assign a new `TokenStream`:
+/// ```
+/// # use proc_macro_utils::assert_tokens;
+/// use manyhow::{attribute, Result, SilentError};
+/// use proc_macro2::TokenStream;
+/// use quote::{quote, ToTokens};
+/// # let input = quote!(input);
+/// let item = quote!(
+///     struct Struct;
+/// );
+/// let output: TokenStream = attribute(
+///     input,
+///     item,
+///     true,
+///     |input: TokenStream,
+///      item: TokenStream,
+///      dummy: &mut TokenStream|
+///      -> Result<TokenStream, SilentError> {
+///         assert_tokens!(dummy.to_token_stream(), {
+///             struct Struct;
+///         });
+///         *dummy = quote! {
+///             struct Struct(HelloWorld);
+///         };
+///         // ..
+///         Err(SilentError)
+///     },
+/// );
+///
+/// assert_tokens! {output, {struct Struct(HelloWorld);}};
+/// ```
+pub fn attribute<
+    Input: AnyTokenStream,
+    Item: AnyTokenStream,
+    Dummy: AnyTokenStream,
+    Output: MacroOutput,
+    Return: AnyTokenStream,
+    Function,
+>(
+    input: impl AnyTokenStream,
+    item: impl AnyTokenStream,
+    item_as_dummy: bool,
+    body: impl AttributeMacroHandler<
+        Function,
+        Item = Item,
+        Input = Input,
+        Dummy = Dummy,
+        Output = Output,
+    >,
+) -> Return {
+    #[allow(unused_mut)]
+    let mut tokens = Dummy::default();
+    let mut tokens = if item_as_dummy {
+        item.clone().into().into()
+    } else {
+        tokens
+    };
+    let mut emitter = Emitter::new();
+    let output = body.call(
+        input.into().into(),
+        item.into().into(),
+        &mut tokens,
+        &mut emitter,
+    );
+    let mut tokens = tokens.into();
+    let mut tokens = match output.convert() {
+        Ok(tokens) => tokens,
+        Err(error) => {
+            error.to_tokens(&mut tokens);
+            tokens
+        }
+    };
+    emitter.to_tokens(&mut tokens);
+    tokens.into()
+}
+
+/// Handles [`proc_macro_attribute`](https://doc.rust-lang.org/reference/procedural-macros.html#attribute-macros)
+/// implementation
+///
+/// Takes any `TokenStream` for `input` and `item` and its return value. If
+/// `#[as_dummy]` is specified on item, it will be used as default
+/// dummy code on error. `body` takes a [`AttributeMacroHandler`] with two
+/// `TokenStream`s or types implementing [`Parse`] parameters and returning a
+/// `TokenStream` or type implementing [`ToTokens`]. And an optional [`&mut
+/// Emitter`](Emitter) and a `&mut TokenStream` for storing a dummy output.
+///
+///
+/// ```
+/// # use proc_macro_utils::assert_tokens;
+/// # use quote::{quote, ToTokens};
+/// use manyhow::{attribute, Emitter, Result};
+/// use proc_macro2::TokenStream;
+/// # let input = quote!();
+/// # let item = quote!();
+/// # let output: TokenStream =
+/// attribute!(input, item, |input: TokenStream,
+///                          item: TokenStream,
+///                          dummy: &mut TokenStream,
+///                          emitter: &mut Emitter|
+///  -> Result {
+///     // ..
+///         # Ok(quote!())
+/// });
+/// ```
+///
+/// *Note:* When `#[as_dummy]` is specified the `dummy: &mut TokenStream` will
+/// be initialized with `item`. To override assign a new `TokenStream`:
+/// ```
+/// # use proc_macro_utils::assert_tokens;
+/// # use syn2 as syn;
+/// use manyhow::{attribute, Result, SilentError};
+/// use proc_macro2::TokenStream;
+/// use quote::{quote, ToTokens};
+/// # let input = quote!(input);
+/// let item = quote!(
+///     struct Struct;
+/// );
+/// let output: TokenStream = attribute!(
+///     input,
+///     #[as_dummy]
+///     item,
+///     |input: TokenStream,
+///      item: syn::ItemStruct,
+///      dummy: &mut TokenStream|
+///      -> Result<syn::ItemStruct, SilentError> {
+///         assert_tokens!(dummy.to_token_stream(), {
+///             struct Struct;
+///         });
+///         *dummy = quote! {
+///             struct Struct(HelloWorld);
+///         };
+///         // ..
+///         Err(SilentError)
+///     },
+/// );
+///
+/// assert_tokens! {output, {struct Struct(HelloWorld);}};
+/// ```
+#[macro_export]
+macro_rules! attribute {
+    ($input:expr, #[as_dummy] $item:expr, $impl:expr $(,)?) => {
+        $crate::__macro_handler!{attribute_transparent; #attr=true input: $input, item: $item.clone(); $impl; dummy: $item}
+    };
+    ($input:expr, $item:expr, $impl:expr $(,)?) => {
+        $crate::__macro_handler!{attribute_transparent; #attr=true input: $input, item: $item; $impl; dummy}
+    };
+}
+
+/// Handles [`proc_macro_derive`](https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros)
+/// implementation.
+///
+/// Use [`derive!`] to support [`Parse`] and [`ToTokens`] as well.
+///
+/// Takes any `TokenStream` for `item` and returns any `TokenStream`. `body`
+/// takes a [`DeriveMacroHandler`] with one `TokenStream` parameter. And an
+/// optional [`&mut Emitter`](Emitter) and `&mut TokenStream` for storing a
+/// dummy output.
+///
+/// ```
+/// # use proc_macro_utils::assert_tokens;
+/// # use quote::{quote, ToTokens};
+/// use manyhow::{derive, Emitter, Result};
+/// use proc_macro2::TokenStream;
+/// # let item = quote!();
+/// # let output: TokenStream =
+/// derive(
+///     item,
+///     |item: TokenStream, dummy: &mut TokenStream, emitter: &mut Emitter| -> Result {
+///         // ..
+///         # Ok(quote!())
+///     },
+/// );
+/// ```
+pub fn derive<
+    Item: AnyTokenStream,
+    Dummy: AnyTokenStream,
+    Output: MacroOutput,
+    Return: AnyTokenStream,
+    Function,
+>(
+    item: impl AnyTokenStream,
+    body: impl DeriveMacroHandler<Function, Item = Item, Dummy = Dummy, Output = Output>,
+) -> Return {
+    let mut tokens = Dummy::default();
+    let mut emitter = Emitter::new();
+    let output = body.call(item.into().into(), &mut tokens, &mut emitter);
+    let mut tokens = tokens.into();
+    let mut tokens = match output.convert() {
+        Ok(tokens) => tokens,
+        Err(error) => {
+            error.to_tokens(&mut tokens);
+            tokens
+        }
+    };
+    emitter.to_tokens(&mut tokens);
+    tokens.into()
+}
+
+/// Handles [`proc_macro_derive`](https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros)
+/// implementation.
+///
+/// Takes any `TokenStream` for `item` and returns any `TokenStream`. `body`
+/// takes a [`DeriveMacroHandler`] with one `TokenStream` or type implementing
+/// [`Parse`] parameter and returns a `TokenStream` or type implementing
+/// [`ToTokens`]. And an optional [`&mut Emitter`](Emitter) and `&mut
+/// TokenStream` for storing a dummy output.
+///
+/// ```
+/// # use proc_macro_utils::assert_tokens;
+/// # use quote::{quote, ToTokens};
+/// # use syn2 as syn;
+/// use manyhow::{derive, Emitter, Result};
+/// use proc_macro2::TokenStream;
+/// # let item = quote!();
+/// # let output: TokenStream =
+/// derive!(item, |item: syn::DeriveInput,
+///                dummy: &mut TokenStream,
+///                emitter: &mut Emitter|
+///  -> Result {
+///     // ..
+///         # Ok(quote!())
+/// });
+/// ```
+#[macro_export]
+macro_rules! derive {
+    ($item:expr, $impl:expr $(,)?) => {
+        $crate::__macro_handler! {derive_transparent; item: $item; $impl}
+    };
+}
+
+/// Handles function like [`proc_macro`](https://doc.rust-lang.org/reference/procedural-macros.html#function-like-procedural-macros)
+/// implementation
+///
+/// Use [`function!`] to support [`Parse`] and [`ToTokens`] as well.
+///
+/// Takes any `TokenStream` for `input` and returns any
+/// `TokenStream`. If `input_as_dummy = true` the item input will be used as
+/// default dummy code on error. `body` takes a [`FunctionMacroHandler`] with
+/// one `TokenStream` parameter. And an optional [`&mut Emitter`](Emitter) and a
+/// `&mut TokenStream` for storing a dummy output.
+///
+/// ```
+/// # use proc_macro_utils::assert_tokens;
+/// # use quote::{quote, ToTokens};
+/// use manyhow::{function, Emitter, Result};
+/// use proc_macro2::TokenStream;
+/// # let input = quote!();
+/// # let output: TokenStream =
+/// function(
+///     input,
+///     false,
+///     |input: TokenStream, dummy: &mut TokenStream, emitter: &mut Emitter| -> Result {
+///         // ..
+///         # Ok(quote!())
+///     },
+/// );
+/// ```
+///
+/// *Note:* When `input_as_dummy = true` the `dummy: &mut TokenStream` will be
+/// initialized with `input`. To override assign a new `TokenStream`:
+/// ```
+/// # use proc_macro_utils::assert_tokens;
+/// use manyhow::{function, Result, SilentError};
+/// use proc_macro2::TokenStream;
+/// use quote::{quote, ToTokens};
+/// let input = quote!(some input);
+/// let output: TokenStream = function(
+///     input,
+///     true,
+///     |input: TokenStream,
+///      dummy: &mut TokenStream|
+///      -> Result<TokenStream, SilentError> {
+///         assert_tokens!(dummy.to_token_stream(), {
+///             some input
+///         });
+///         *dummy = quote! {
+///             another input
+///         };
+///         // ..
+///         Err(SilentError)
+///     },
+/// );
+///
+/// assert_tokens! {output, {another input}};
+/// ```
+pub fn function<
+    Input: AnyTokenStream,
+    Dummy: AnyTokenStream,
+    Output: MacroOutput,
+    Return: AnyTokenStream,
+    Function,
+>(
+    input: impl AnyTokenStream,
+    input_as_dummy: bool,
+    body: impl FunctionMacroHandler<Function, Input = Input, Dummy = Dummy, Output = Output>,
+) -> Return {
+    let mut tokens = if input_as_dummy {
+        input.clone().into().into()
+    } else {
+        Dummy::default()
+    };
+    let mut emitter = Emitter::new();
+    let output = body.call(input.into().into(), &mut tokens, &mut emitter);
+    let mut tokens = tokens.into();
+    let mut tokens = match output.convert() {
+        Ok(tokens) => tokens,
+        Err(error) => {
+            error.to_tokens(&mut tokens);
+            tokens
+        }
+    };
+    emitter.to_tokens(&mut tokens);
+    tokens.into()
+}
+
+/// Handles function like [`proc_macro`](https://doc.rust-lang.org/reference/procedural-macros.html#function-like-procedural-macros)
+/// implementation
+///
+/// Takes any `TokenStream` for `input` and returns any `TokenStream`. If
+/// `#[as_dummy]` is specified on input, it will be used as default
+/// dummy code on error. `body` takes a [`FunctionMacroHandler`] with one
+/// `TokenStream` or type implementing [`Parse`] parameter and returns a
+/// `TokenStream` or type implementing [`ToTokens`]. And an optional [`&mut
+/// Emitter`](Emitter) and a `&mut TokenStream` for storing a dummy output.
+///
+/// ```
+/// # use proc_macro_utils::assert_tokens;
+/// # use quote::{quote, ToTokens};
+/// # use syn2 as syn;
+/// use manyhow::{function, Emitter, Result};
+/// use proc_macro2::TokenStream;
+/// # let input = quote!();
+/// # let output: TokenStream =
+/// function!(input, |input: syn::Item,
+///                   dummy: &mut TokenStream,
+///                   emitter: &mut Emitter|
+///  -> Result<syn::ItemImpl> {
+///     // ..
+///         # manyhow::bail!("unimplemented")
+/// });
+/// ```
+///
+/// *Note:* When `#[as_dummy]` is specified on the input, the `dummy: &mut
+/// TokenStream` will be initialized with `input`. To override assign a new
+/// `TokenStream`:
+///
+/// ```
+/// use proc_macro_utils::assert_tokens;
+/// use manyhow::{function, Result, SilentError};
+/// use proc_macro2::TokenStream;
+/// use quote::{quote, ToTokens};
+///
+/// let input = quote!(some input);
+/// let output: TokenStream = function!(
+///     #[as_dummy] input,
+///     |input: TokenStream, dummy: &mut TokenStream|
+///      -> Result<TokenStream, SilentError> {
+///         assert_tokens!(dummy.to_token_stream(), {
+///             some input
+///         });
+///         *dummy = quote! {
+///             another input
+///         };
+///         // ..
+///         Err(SilentError)
+///     },
+/// );
+///
+/// assert_tokens! {output, {another input}};
+/// ```
+#[macro_export]
+macro_rules! function {
+    (#[as_dummy] $input:expr, $impl:expr $(,)?) => {
+        $crate::__macro_handler! {function_transparent; input: $input; $impl; dummy: $input}
+    };
+    ($input:expr, $impl:expr $(,)?) => {
+        $crate::__macro_handler! {function_transparent; input: $input; $impl; dummy}
+    };
+}
+
+#[test]
+fn function_macro() {
+    use proc_macro::TokenStream as TokenStream1;
+    use quote::quote;
+    // proc_macro2::TokenStream
+    let output: TokenStream =
+        function!(quote!(hello), |input: TokenStream| -> TokenStream { input });
+    assert_eq!(output.to_string(), "hello");
+    // proc_macro::TokenStream do not run :D
+    if false {
+        let _: TokenStream1 = function!(
+            TokenStream1::from(quote!(hello)),
+            |input: TokenStream1| -> TokenStream1 { input }
+        );
+    }
+
+    #[cfg(feature = "syn2")]
+    {
+        use quote::ToTokens;
+        let output: TokenStream = function!(
+            #[as_dummy]
+            quote!(hello;),
+            |input: syn2::LitInt| -> TokenStream { input.into_token_stream() }
+        );
+        assert_eq!(
+            output.to_string(),
+            quote!(hello; ::core::compile_error! { "expected integer literal" }).to_string()
+        );
+        let output: TokenStream = function!(quote!(20), |_input: syn2::LitInt| -> syn2::Ident {
+            syn2::parse_quote!(hello)
+        });
+        assert_eq!(output.to_string(), "hello");
+    }
+}
+
+macro_rules! macro_input {
+    ($MacroInput:ident; $($input:ident: $Input:ident),+; $a:literal; $name:literal; $token_streams:literal) => {
+        /// Input of
+        #[doc = $a]
+        #[doc = $name]
+        /// proc-macro
+        ///
+        /// Note: for `TokenStream` either [`proc_macro::TokenStream`] or
+        /// [`proc_macro2::TokenStream`] can be used.
+        ///
+        /// Trait is implemented for any [`function`](FnOnce), taking in
+        #[doc = concat!($token_streams, ".")]
+        /// Additionally, they can take optionally in any order a [`&mut
+        /// Emitter`](Emitter) which allows emitting errors without returning early. And
+        /// a `&mut TokenStream` to return a dummy `TokenStream` on failure.
+        ///
+        /// When used with
+        #[doc = concat!("[`", $name, "()`]")]
+        /// it must return a type implementing [`MacroOutput`], with
+        #[doc = concat!("[`", $name, "!`]")]
+        /// it can accept types implementing [`Parse`] and return types
+        /// implementing [`ToTokens`](quote::ToTokens).
+        #[allow(missing_docs)]
+        pub trait $MacroInput<Function> {
+            $(type $Input;)+
+            type Dummy;
+            type Output;
+            #[allow(clippy::missing_errors_doc)]
+            fn call(
+                self,
+                $(item: Self::$Input,)+
+                dummy: &mut Self::Dummy,
+                emitter: &mut Emitter,
+            ) -> Self::Output;
+        }
+
+        macro_input_impl!([$($Input,)+ Dummy: Clone]; $MacroInput; $($input: $Input),*; &mut Dummy, &mut Emitter; dummy: Dummy dummy; emitter emitter);
+        macro_input_impl!([$($Input,)+ Dummy: Clone]; $MacroInput; $($input: $Input),*; &mut Dummy; dummy: Dummy dummy; _emitter);
+        macro_input_impl!([$($Input),+]; $MacroInput; $($input: $Input),*; &mut Emitter; _dummy: TokenStream; emitter emitter);
+        macro_input_impl!([$($Input),+]; $MacroInput; $($input: $Input),*; ; _dummy: TokenStream; _emitter);
+    };
+}
+
+macro_rules! macro_input_impl {
+    ([$($gen:tt)*]; $MacroInput:ident; $($input:ident: $Input:ident),+; $($Extra:ty),*; $dummy1:ident: $Dummy:ident $($dummy2:ident)?; $emitter1:ident $($emitter2:ident)?) => {
+        impl<$($gen)*, Output, Function> $MacroInput<($($Input,)+ $($Extra,)* Output)> for Function
+        where
+            Function: Fn($($Input,)+ $($Extra,)*) -> Output,
+        {
+            type Dummy = $Dummy;
+            $(type $Input = $Input;)*
+            type Output = Output;
+
+            fn call(
+                self,
+                $($input: Self::$Input,)*
+                $dummy1: &mut Self::Dummy,
+                $emitter1: &mut Emitter,
+            ) -> Self::Output {
+                self($($input,)+ $($dummy2,)? $($emitter2,)?)
+            }
+        }
+
+    }
+}
+
+macro_input!(FunctionMacroHandler; input: Input; "a"; "function"; "one `TokenStream`");
+macro_input!(DeriveMacroHandler; item: Item; "a"; "derive"; "one `TokenStream`");
+macro_input!(AttributeMacroHandler; input: Input, item: Item; "an"; "attribute"; "two `TokenStream`s");
+
+#[rustfmt::skip]
+#[allow(clippy::doc_markdown)]
+/// Output of a macro handler.
+///
+/// Enables support for returning any [`TokenStream`](AnyTokenStream) or
+/// <code>[Result]<[TokenStream](AnyTokenStream), [impl ToTokensError](ToTokensError)></code>
+/// from a proc-macro implementation.
+pub trait MacroOutput {
+    /// Handles conversion into a <code>[Result]<[TokenStream](AnyTokenStream), [Error]></code>.
+    #[allow(clippy::missing_errors_doc)]
+    fn convert(self) -> Result<TokenStream, Error>;
+}
+
+impl<T: AnyTokenStream> MacroOutput for T {
+    fn convert(self) -> Result<TokenStream, Error> {
+        Ok(self.into())
+    }
+}
+
+impl<T: MacroOutput, E: ToTokensError + 'static> MacroOutput for Result<T, E> {
+    fn convert(self) -> Result<TokenStream, Error> {
+        self.map_err(Error::from).and_then(MacroOutput::convert)
+    }
+}
diff --git a/third-party/manyhow/src/macro_rules.rs b/third-party/manyhow/src/macro_rules.rs
new file mode 100644
index 0000000..e29d222
--- /dev/null
+++ b/third-party/manyhow/src/macro_rules.rs
@@ -0,0 +1,323 @@
+#[cfg(doc)]
+use proc_macro2::Span;
+#[cfg(doc)]
+use quote::ToTokens;
+
+#[cfg(doc)]
+use crate::{Emitter, Error, ErrorMessage, SpanRanged};
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __error_message_internal {
+    ((cs($($fmt:tt)*)$(.$fn:ident($($fmt_fn:tt)*))*), (), ()) => {
+        $crate::ErrorMessage::call_site($($fmt)*)
+            $(.attachment(::core::stringify!($fn), $($fmt_fn)*))*
+    };
+    ((new($span:expr)($($fmt:tt)*)$(.$fn:ident($($fmt_fn:tt)*))*), (), ()) => {
+        $crate::ErrorMessage::new(
+            $crate::span_range!($span),
+            $($fmt)*
+        )
+            $(.attachment(::core::stringify!($fn), $($fmt_fn)*))*
+    };
+    // ident = expr
+    ($head:tt, ($($fmt:tt)*), (, $ident:ident = $expr:expr, $($tail:tt)*)) => {
+        $crate::__error_message_internal!($head, ($($fmt)*, $ident = $expr), (, $($tail)*))
+    };
+    ($head:tt, ($($fmt:tt)*), (, $ident:ident = $expr:expr; $($tail:tt)*)) => {
+        $crate::__error_message_internal!($head, ($($fmt)*, $ident = $expr), (; $($tail)*))
+    };
+    ($head:tt, ($($fmt:tt)*), (, $ident:ident = $expr:expr)) => {
+        $crate::__error_message_internal!($head, ($($fmt)*, $ident = $expr), ())
+    };
+    // expr,
+    ($head:tt, ($($fmt:tt)*), (, $expr:expr, $($tail:tt)*)) => {
+        $crate::__error_message_internal!($head, ($($fmt)*, $expr), (, $($tail)*))
+    };
+    ($head:tt, ($($fmt:tt)*), (, $expr:expr; $($tail:tt)*)) => {
+        $crate::__error_message_internal!($head, ($($fmt)*, $expr), (; $($tail)*))
+    };
+    ($head:tt, ($($fmt:tt)*), (, $expr:expr)) => {
+        $crate::__error_message_internal!($head, ($($fmt)*, $expr), ())
+    };
+    // ; ident = "format", arguments
+    (($($head:tt)*), $fmt:tt, ($(,)?$(;)?)) => {
+        $crate::__error_message_internal!(($($head)*(::core::format_args!$fmt)), (), ())
+    };
+    (($($head:tt)*), $fmt:tt, ($(,)?; $attachment:ident = $fmt_str:literal $($tail:tt)*)) => {
+        $crate::__error_message_internal!(($($head)*(::core::format_args!$fmt).$attachment), ($fmt_str), ($($tail)*))
+    };
+}
+
+/// Creates an [`ErrorMessage`], comparable to the [`anyhow!`](https://docs.rs/anyhow/latest/anyhow/macro.anyhow.html) macro
+///
+/// If the first argument is not a literal it is taken as the span of the error.
+/// The span expression can **either** implement [`SpanRanged`] or implement
+/// [`ToTokens`]. Otherwise, [`Span::call_site`] is used.
+///
+/// ```
+/// # use proc_macro2::Span;
+/// # use quote::quote;
+/// # use manyhow::error_message;
+/// assert_eq!(
+///     error_message!("format {} string{named}", "<3", named = "!").to_string(),
+///     "format <3 string!"
+/// );
+/// // Span can either be `proc_macro::Span` or `proc_macro2::Span`
+/// assert_eq!(
+///     error_message!(Span::call_site(), "spanned error").to_string(),
+///     "spanned error"
+/// );
+/// # if false {
+/// // Or any expression implementing `quote::ToTokens`
+/// assert_eq!(
+///     error_message!(quote!(some tokens), "spanned error").to_string(),
+///     "spanned error"
+/// );
+/// # }
+/// ```
+///
+/// On top of the standard [`format_args!`] parameters additional attachments
+/// can be specified delimited with `;`.
+///
+/// ```
+/// # use proc_macro2::Span;
+/// # use quote::quote;
+/// # use manyhow::error_message;
+/// assert_eq!(
+///     error_message!(
+///         "format {} string{named}", "<3", named = "!";
+///         error = "some additional error";
+///         info = "some info as well";
+///         custom_attachment = "amazing"
+///     ).to_string(),
+///     "format <3 string!
+///
+///   = error: some additional error
+///   = info: some info as well
+///   = custom_attachment: amazing
+/// "
+/// );
+/// ```
+#[macro_export]
+macro_rules! error_message {
+    ($fmt:literal $($tt:tt)*) => {
+        $crate::__error_message_internal!((cs), ($fmt), ($($tt)*))
+    };
+    ($span:expr, $fmt:literal $($tt:tt)*) => {
+        $crate::__error_message_internal!((new($span)), ($fmt), ($($tt)*))
+    };
+}
+
+/// Exit by returning error, matching [`anyhow::bail!`](https://docs.rs/anyhow/latest/anyhow/macro.bail.html).
+///
+/// The syntax is identical to [`error_message!`], the only difference is, that
+/// a single expression with an error is supported as well.
+/// ```should_panic
+/// # use manyhow::bail;
+/// # use proc_macro2::Span;
+/// # use syn2 as syn;
+/// bail!("an error message"; error = "with attachments");
+/// let span = Span::call_site();
+/// bail!(span, "error message");
+/// let error = syn::Error::new(Span::call_site(), "an error");
+/// bail!(error);
+/// # Ok::<_, manyhow::Error>(())
+/// ```
+#[macro_export]
+macro_rules! bail {
+    ($msg:literal) => {
+        return ::core::result::Result::Err($crate::error_message!($msg).into())
+    };
+    ($error:expr) => {
+        return ::core::result::Result::Err($error.into())
+    };
+    ($($tt:tt)*) => {
+        return ::core::result::Result::Err($crate::error_message!($($tt)*).into())
+    };
+}
+
+/// Return early with an error, if a condition is not satisfied, matching
+/// [`anyhow::ensure!`](https://docs.rs/anyhow/latest/anyhow/macro.ensure.html).
+///
+/// The syntax is identical to [`bail!`], with an additional leading condition.
+///
+/// Additional to a boolean expression, the expression can also be a `let ... =
+/// ...` pattern matching, and will expand to `let ... else`.
+/// ```
+/// # use manyhow::ensure;
+/// ensure!(true, "an error message"; help = "with attachments");
+///
+/// ensure!(let Some(a) = Some(1), "error");
+/// assert_eq!(a, 1);
+///
+/// # Ok::<_, manyhow::Error>(())
+/// ```
+/// ```should_panic
+/// # use manyhow::ensure;
+/// # use proc_macro2::Span;
+/// # use syn2 as syn;
+/// let span = Span::call_site();
+/// ensure!(false, span, "error message");
+/// let error = syn::Error::new(Span::call_site(), "an error");
+/// ensure!(false, error);
+/// # Ok::<_, manyhow::Error>(())
+/// ```
+#[macro_export]
+macro_rules! ensure {
+    ($cond:expr, $($bail_args:tt)*) => {
+        if !$cond {
+            $crate::bail!($($bail_args)*);
+        }
+    };
+    (let $pat:pat = $expr:expr, $($bail_args:tt)*) => {
+        let $pat = $expr else {
+            $crate::bail!($($bail_args)*);
+        };
+    };
+}
+
+/// Push an error to an emitter.
+///
+/// The syntax is identical to [`error_message!`] and [`bail!`], but the first
+/// argument is the [`Emitter`].
+/// ```
+/// # use manyhow::{emit, Emitter};
+/// # use proc_macro2::Span;
+/// # use syn2 as syn;
+/// let mut emitter = Emitter::new();
+/// emit!(emitter, "an error message");
+/// emit!(emitter, "an error message"; error = "with attachments");
+/// let span = Span::call_site();
+/// emit!(emitter, span, "error message");
+/// let error = syn::Error::new(Span::call_site(), "an error");
+/// emit!(emitter, error);
+/// ```
+///
+/// It can also be used with [`Error`].
+/// ```
+/// # use manyhow::{emit, error_message, Error};
+/// # use proc_macro2::Span;
+/// # use syn2 as syn;
+/// let mut error: Error = error_message!("initial error").into();
+/// emit!(error, "an error message");
+/// ```
+///
+/// Or any collection implementing [`Extend`].
+/// ```
+/// # use manyhow::emit;
+/// # use proc_macro2::Span;
+/// # use syn2 as syn;
+/// let mut errors = Vec::new();
+/// emit!(errors, "an error message");
+/// ```
+#[macro_export]
+macro_rules! emit {
+    ($emitter:expr, $msg:literal) => {
+        $emitter.extend(::core::iter::once::<$crate::ErrorMessage>($crate::error_message!($msg)));
+    };
+    ($emitter:expr, $error:expr) => {
+        $emitter.extend(::core::iter::once($error));
+    };
+    ($emitter:expr, $($tt:tt)*) => {
+        $emitter.extend(::core::iter::once::<$crate::ErrorMessage>($crate::error_message!($($tt)*).into()));
+    };
+}
+
+#[cfg(test)]
+mod test {
+    use proc_macro::Span;
+    use quote::quote;
+
+    use crate::{Emitter, ErrorMessage};
+
+    macro_rules! returned {
+        ($ty:ty, $expr:expr) => {
+            #[allow(unreachable_code)]
+            (|| -> $ty {
+                $expr;
+                unreachable!();
+            })()
+        };
+    }
+    #[test]
+    fn bail() {
+        assert_eq!(
+            returned!(Result<(), ErrorMessage>, bail!("format"))
+                .unwrap_err()
+                .to_string(),
+            "format"
+        );
+        assert_eq!(
+            returned!(Result<(), ErrorMessage>, bail!("format {}", 1))
+                .unwrap_err()
+                .to_string(),
+            "format 1"
+        );
+        let b = "ho";
+        assert_eq!(
+            returned!(Result<(), ErrorMessage>, bail!("format {} {a} {} {b}", 1, 2, a = 4))
+                .unwrap_err()
+                .to_string(),
+            "format 1 4 2 ho"
+        );
+    }
+
+    #[test]
+    fn error_message() {
+        assert_eq!(error_message!("test").to_string(), "test");
+        assert_eq!(error_message!("test";).to_string(), "test");
+        assert_eq!(
+            error_message!(
+                "test";
+                error = "hello {} {a}", 1 + 4, a = ""
+            )
+            .to_string(),
+            "test\n\n  = error: hello 5 \n"
+        );
+        assert_eq!(
+            error_message!(
+                "test";
+                error = "hello {} {a}", 1 + 4, a = "";
+            )
+            .to_string(),
+            "test\n\n  = error: hello 5 \n"
+        );
+        assert_eq!(
+            error_message!(
+                "test";
+                error = "hello {} {a}", 1 + 4, a = "",;
+                hint = "a hint"
+            )
+            .to_string(),
+            "test\n\n  = error: hello 5 \n  = hint: a hint\n"
+        );
+    }
+
+    #[test]
+    fn emit() {
+        let mut emitter = Emitter::new();
+        emit!(emitter, "an error message"; error = "with attachments");
+        let span = proc_macro2::Span::call_site();
+        emit!(emitter, span, "error message");
+        #[cfg(feature = "syn2")]
+        {
+            let error = syn2::Error::new(proc_macro2::Span::call_site(), "an error");
+            emit!(emitter, error);
+        }
+    }
+
+    // Only tests that it compiles
+    fn _error_message_spanned() {
+        let span = Span::call_site();
+        _ = error_message!(span, "test");
+
+        let span = proc_macro::Span::call_site();
+        _ = error_message!(span, "test");
+
+        let tokens = quote!(test);
+        _ = error_message!(tokens, "an error message",);
+        _ = error_message!(tokens, "an error message",;);
+        _ = error_message!(tokens, "an error message",; warning="and a warning";);
+    }
+}
diff --git a/third-party/manyhow/src/parse_to_tokens.rs b/third-party/manyhow/src/parse_to_tokens.rs
new file mode 100644
index 0000000..8c665b3
--- /dev/null
+++ b/third-party/manyhow/src/parse_to_tokens.rs
@@ -0,0 +1,172 @@
+#![allow(missing_docs, clippy::pedantic)]
+use std::convert::Infallible;
+use std::marker::PhantomData;
+
+use proc_macro2::TokenStream;
+
+use crate::{
+    AnyTokenStream, AttributeMacroHandler, DeriveMacroHandler, Emitter, FunctionMacroHandler,
+    ToTokensError,
+};
+pub trait ManyhowParse<T> {
+    fn manyhow_parse(&self, input: impl AnyTokenStream, attr: bool) -> Result<T, TokenStream>;
+}
+pub trait ManyhowToTokens<T> {
+    fn manyhow_to_tokens(&self, input: T, tokens: &mut TokenStream);
+}
+pub trait ManyhowTry<T> {
+    type Ok;
+    type Err;
+    fn manyhow_try(&self, value: T) -> Result<Self::Ok, Self::Err>;
+}
+
+pub struct WhatType<T>(PhantomData<T>);
+
+impl<T> WhatType<T> {
+    /// Always panics
+    pub fn identify(&self) -> Result<T, TokenStream> {
+        unimplemented!("DON'T YOU DARE CALL ME")
+    }
+
+    pub fn from(_ty: &T) -> Self {
+        Self(PhantomData)
+    }
+
+    #[allow(clippy::new_without_default)]
+    pub fn new() -> Self {
+        Self(PhantomData)
+    }
+}
+
+impl<T> Clone for WhatType<T> {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl<T> Copy for WhatType<T> {}
+
+impl<T: Into<TokenStream> + From<TokenStream>> ManyhowParse<T> for WhatType<T> {
+    fn manyhow_parse(&self, input: impl AnyTokenStream, _attr: bool) -> Result<T, TokenStream> {
+        Ok(input.into().into())
+    }
+}
+
+impl ManyhowToTokens<TokenStream> for WhatType<TokenStream> {
+    fn manyhow_to_tokens(&self, input: TokenStream, tokens: &mut TokenStream) {
+        tokens.extend(input);
+    }
+}
+
+impl ManyhowToTokens<proc_macro::TokenStream> for WhatType<proc_macro::TokenStream> {
+    fn manyhow_to_tokens(&self, input: proc_macro::TokenStream, tokens: &mut TokenStream) {
+        tokens.extend(TokenStream::from(input));
+    }
+}
+
+impl<E: ToTokensError> ManyhowToTokens<E> for WhatType<E> {
+    fn manyhow_to_tokens(&self, input: E, tokens: &mut TokenStream) {
+        input.to_tokens(tokens);
+    }
+}
+
+impl<T, E> ManyhowTry<Result<T, E>> for WhatType<Result<T, E>> {
+    type Err = E;
+    type Ok = T;
+
+    fn manyhow_try(&self, value: Result<T, E>) -> Result<Self::Ok, Self::Err> {
+        value
+    }
+}
+
+impl<T> ManyhowTry<T> for &WhatType<T> {
+    type Err = Infallible;
+    type Ok = T;
+
+    fn manyhow_try(&self, value: T) -> Result<Self::Ok, Self::Err> {
+        Ok(value)
+    }
+}
+
+#[cfg(feature = "syn2")]
+impl<T: syn2::parse::Parse> ManyhowParse<T> for &WhatType<T> {
+    fn manyhow_parse(&self, input: impl AnyTokenStream, attr: bool) -> Result<T, TokenStream> {
+        let input = input.into();
+        let empty = input.is_empty();
+        syn2::parse2(input).map_err(|e| {
+            let mut e = e.into_compile_error();
+            if attr && empty {
+                error_message!("while parsing attribute argument (`#[... (...)]`)")
+                    .to_tokens(&mut e)
+            }
+            e
+        })
+    }
+}
+#[cfg(feature = "syn2")]
+impl<T: quote::ToTokens> ManyhowToTokens<T> for &WhatType<T> {
+    fn manyhow_to_tokens(&self, input: T, tokens: &mut TokenStream) {
+        input.to_tokens(tokens);
+    }
+}
+
+#[cfg(feature = "syn2")]
+#[test]
+#[allow(unused)]
+fn test_inference() {
+    use syn2::parse::Parse;
+
+    if false {
+        let wt = &WhatType::new();
+        let ts: proc_macro::TokenStream = wt.manyhow_parse(quote::quote!(test), false).unwrap();
+        let wt = &WhatType::new();
+        if false {
+            let wt: Result<syn2::Ident, _> = wt.identify();
+        }
+        let ts: syn2::Ident = wt.manyhow_parse(quote::quote!(test), false).unwrap();
+
+        struct Parsable;
+        impl Parse for Parsable {
+            fn parse(input: syn2::parse::ParseStream) -> syn2::Result<Self> {
+                todo!()
+            }
+        }
+        let wt = &WhatType::new();
+        let _: Result<Parsable, _> = wt.identify();
+        let ts = wt.manyhow_parse(quote::quote!(test), false).unwrap();
+    }
+}
+
+macro_rules! transparent_handlers {
+    ($name:ident; $MacroInput:ident; $($input:ident: $Input:ident $($context:expr)?),*; $($dummy:ident)?) => {
+        /// Internal implementation for macro.
+        pub fn $name<$($Input,)* Dummy: AnyTokenStream, Output, Function,>(
+            $($input: Result<$Input, TokenStream>,)*
+            $($dummy: Option<impl AnyTokenStream>,)?
+            body: impl $MacroInput<Function, $($Input = $Input,)* Dummy = Dummy, Output = Output>,
+        ) -> Result<(Output, TokenStream, TokenStream), TokenStream> {
+            // use $crate::ToTokensError as _;
+            #[allow(unused)]
+            let mut dummy = TokenStream::new();
+            $(let mut dummy = $dummy.unwrap_or_default().into();)?
+            $(let $input = match $input {
+                Ok($input) => $input,
+                Err(tokens) => {
+                    dummy.extend(tokens);
+                    $($crate::error_message!($context).to_tokens(&mut dummy);)?
+                    return Err(dummy);
+                }
+            };)*
+            let mut dummy = dummy.into();
+            let mut emitter = Emitter::new();
+            let output = body.call($($input,)+ &mut dummy, &mut emitter);
+            let mut tokens = TokenStream::new();
+            emitter.to_tokens(&mut tokens);
+            Ok((output, tokens, dummy.into()))
+        }
+    };
+}
+
+transparent_handlers! { function_transparent; FunctionMacroHandler; input: Input; dummy }
+transparent_handlers! { derive_transparent; DeriveMacroHandler; item: Item;}
+transparent_handlers! { attribute_transparent; AttributeMacroHandler; input: Input, item: Item; dummy }
diff --git a/third-party/manyhow/src/span_ranged.rs b/third-party/manyhow/src/span_ranged.rs
new file mode 100644
index 0000000..221b883
--- /dev/null
+++ b/third-party/manyhow/src/span_ranged.rs
@@ -0,0 +1,208 @@
+use std::ops::Range;
+
+use proc_macro2::Span;
+use quote::ToTokens;
+
+#[cfg(doc)]
+use crate::ErrorMessage;
+
+/// Get a [`Range`](std::ops::Range)[`<Span>`](proc_macro2::Span) from a
+/// type that **either** implements [`SpanRanged`] or [`ToTokens`] (**NOT**
+/// both).
+#[macro_export]
+macro_rules! span_range {
+    ($span:expr) => {{
+        // Warning is triggered if span is incorrect type
+        #[allow(unused_imports)]
+        use $crate::__private::*;
+        ($span).FIRST_ARG_MUST_IMPLEMENT_SpanRanged_OR_ToTokens()
+    }};
+}
+
+/// Returns the [`Range`](Range)[`<Span>`](Span) from the start to the end of
+/// multi-token structures.
+///
+/// `start` and `end` can be the same when called on single Tokens or [`Span`].
+///
+/// Due to compiler limitations, it is currently not possible to implement
+/// `SpanRanged for T: ToTokens`, therefor there is
+/// [`to_tokens_span_range()`].
+///
+/// For types that **either** implement [`SpanRanged`] or [`ToTokens`] (but
+/// **NOT** both) the [`span_range!`] macro can be used as well.
+///
+/// # Motivation
+/// This is superior to a normal [`Span`] (at least until [`Span::join`] works
+/// on stable), because it leads to better error messages:
+///
+/// Given the following expression
+/// ```
+/// let a = |something: usize| something;
+/// ```
+///
+/// [`ErrorMessage::new(first_pipe_span, "error message")`](ErrorMessage::new)
+/// would result in something like
+///
+/// ```text
+/// error: error message
+///
+/// let a = |something: usize| something;
+///         ^
+/// ```
+///
+/// While [`ErrorMessage::new(first_pipe_span..something_span,
+/// "error message")`](ErrorMessage::new) would improve the error message to:
+/// ```text
+/// error: error message
+///
+/// let a = |something: usize| something;
+///         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+/// ```
+pub trait SpanRanged {
+    /// Returns the [`Range`](Range)[`<Span>`](Span) fully encompasing `self`
+    fn span_range(&self) -> Range<Span>;
+
+    /// Returns [`Self::span_range`] as a single span if possible, currently
+    /// only possible on nightly. [more](proc_macro2::Span::join)
+    fn span_joined(&self) -> Option<Span> {
+        let range = self.span_range();
+        range.start.join(range.end)
+    }
+
+    #[doc(hidden)]
+    #[deprecated]
+    fn joined(&self) -> Option<Span> {
+        self.span_joined()
+    }
+}
+
+impl<T: SpanRanged> SpanRanged for &T {
+    fn span_range(&self) -> Range<Span> {
+        (*self).span_range()
+    }
+}
+
+impl<T: SpanRanged> SpanRanged for Option<T> {
+    fn span_range(&self) -> Range<Span> {
+        self.as_ref()
+            .map_or_else(|| Span::call_site().span_range(), SpanRanged::span_range)
+    }
+}
+
+impl<A: SpanRanged, B: SpanRanged> SpanRanged for (A, B) {
+    fn span_range(&self) -> Range<Span> {
+        (self.0.span_range().start)..(self.1.span_range().end)
+    }
+}
+
+impl SpanRanged for Span {
+    fn span_range(&self) -> Range<Span> {
+        *self..*self
+    }
+}
+impl SpanRanged for proc_macro::Span {
+    fn span_range(&self) -> Range<Span> {
+        (*self).into()..(*self).into()
+    }
+}
+
+impl<T: SpanRanged> SpanRanged for Range<T> {
+    fn span_range(&self) -> Range<Span> {
+        self.start.span_range().start..self.end.span_range().end
+    }
+}
+
+impl SpanRanged for proc_macro::TokenStream {
+    fn span_range(&self) -> Range<Span> {
+        let mut this = self.clone().into_iter();
+        let first = this
+            .next()
+            .as_ref()
+            .map_or_else(proc_macro::Span::call_site, proc_macro::TokenTree::span);
+
+        let last = this
+            .last()
+            .as_ref()
+            .map_or(first, proc_macro::TokenTree::span);
+        first.into()..last.into()
+    }
+}
+
+/// Implementation of [`SpanRanged`](SpanRanged)` for T: `[`ToTokens`]
+///
+/// This is necessary to put in a standalone function due to compiler
+/// limitations.
+pub fn to_tokens_span_range(tokens: impl ToTokens) -> Range<Span> {
+    proc_macro::TokenStream::from(tokens.to_token_stream()).span_range()
+}
+
+#[doc(hidden)]
+pub trait SpanRangedToSpanRange {
+    #[allow(non_snake_case)]
+    fn FIRST_ARG_MUST_IMPLEMENT_SpanRanged_OR_ToTokens(&self) -> Range<Span>;
+}
+impl<T: SpanRanged> SpanRangedToSpanRange for T {
+    #[allow(non_snake_case)]
+    fn FIRST_ARG_MUST_IMPLEMENT_SpanRanged_OR_ToTokens(&self) -> Range<Span> {
+        self.span_range()
+    }
+}
+
+#[doc(hidden)]
+pub trait ToTokensToSpanRange {
+    #[allow(non_snake_case)]
+    fn FIRST_ARG_MUST_IMPLEMENT_SpanRanged_OR_ToTokens(&self) -> Range<Span>;
+}
+impl<T: ToTokens> ToTokensToSpanRange for T {
+    #[allow(non_snake_case)]
+    fn FIRST_ARG_MUST_IMPLEMENT_SpanRanged_OR_ToTokens(&self) -> Range<Span> {
+        let mut this = self.to_token_stream().into_iter();
+        let first = this
+            .next()
+            .as_ref()
+            .map_or_else(proc_macro2::Span::call_site, proc_macro2::TokenTree::span);
+
+        let last = this
+            .last()
+            .as_ref()
+            .map_or(first, proc_macro2::TokenTree::span);
+        first..last
+    }
+}
+
+#[doc(hidden)]
+pub trait ToTokensTupleToSpanRange {
+    #[allow(non_snake_case)]
+    fn FIRST_ARG_MUST_IMPLEMENT_SpanRanged_OR_ToTokens(&self) -> Range<Span>;
+}
+impl<A: ToTokens, B: ToTokens> ToTokensTupleToSpanRange for (A, B) {
+    #[allow(non_snake_case)]
+    fn FIRST_ARG_MUST_IMPLEMENT_SpanRanged_OR_ToTokens(&self) -> Range<Span> {
+        let first = self
+            .0
+            .to_token_stream()
+            .into_iter()
+            .next()
+            .as_ref()
+            .map_or_else(proc_macro2::Span::call_site, proc_macro2::TokenTree::span);
+
+        let last = self
+            .1
+            .to_token_stream()
+            .into_iter()
+            .last()
+            .as_ref()
+            .map_or(first, proc_macro2::TokenTree::span);
+
+        first..last
+    }
+}
+
+#[cfg(test)]
+mod test {
+    #[test]
+    fn test() {
+        span_range!(1);
+        span_range!((1, 2));
+    }
+}
diff --git a/third-party/proc-macro-error2/.gitignore b/third-party/proc-macro-error2/.gitignore
new file mode 100644
index 0000000..5e81b66
--- /dev/null
+++ b/third-party/proc-macro-error2/.gitignore
@@ -0,0 +1,4 @@
+/target
+**/*.rs.bk
+Cargo.lock
+.fuse_hidden*
diff --git a/third-party/proc-macro-error2/CHANGELOG.md b/third-party/proc-macro-error2/CHANGELOG.md
new file mode 100644
index 0000000..4f22c85
--- /dev/null
+++ b/third-party/proc-macro-error2/CHANGELOG.md
@@ -0,0 +1,180 @@
+# v2.0.1 (2024-09-06)
+
+* Fixed a span location issue due to mistake in refactoring (#2)
+
+# v2.0.0 (2024-09-05)
+
+No changes, simply releasing pre-release as full release.
+
+# v2.0.0-pre.1 (2024-09-01)
+
+* __Crate has been renamed to `proc-macro-error2`, due to the old maintainer's inactivity.__
+
+* `syn` has been upgraded to `2`
+* MSRV has been bumped to `1.61`
+* Warnings have been fixed, including `clippy::pedantic` lints
+* CI has been converted to GitHub actions, and testing infrastructure significantly simplified.
+* Automatic nightly detection has been removed, use the `nightly` feature for improved diagnostics at the cost of stablity.
+
+# v1.0.4 (2020-7-31)
+
+* `SpanRange` facility is now public.
+* Docs have been improved.
+* Introduced the `syn-error` feature so you can opt-out from the `syn` dependency.
+
+# v1.0.3 (2020-6-26)
+
+* Corrected a few typos.
+* Fixed the `emit_call_site_warning` macro.
+
+# v1.0.2 (2020-4-9)
+
+* An obsolete note was removed from documentation.
+
+# v1.0.1 (2020-4-9)
+
+* `proc-macro-hack` is now well tested and supported. Not sure about `proc-macro-nested`,
+  please fill a request if you need it.
+* Fixed `emit_call_site_error`.
+* Documentation improvements.
+
+# v1.0.0 (2020-3-25)
+
+I believe the API can be considered stable because it's been a few months without
+breaking changes, and I also don't think this crate will receive much further evolution.
+It's perfect, admit it.
+
+Hence, meet the new, stable release!
+
+### Improvements
+
+* Supported nested `#[proc_macro_error]` attributes. Well, you aren't supposed to do that,
+  but I caught myself doing it by accident on one occasion and the behavior was... surprising.
+  Better to handle this smooth.
+
+# v0.4.12 (2020-3-23)
+
+* Error message on macros' misuse is now a bit more understandable.
+
+# v0.4.11 (2020-3-02)
+
+* `build.rs` no longer fails when `rustc` date could not be determined,
+  (thanks to [`Fabian Möller`](https://gitlab.com/CreepySkeleton/proc-macro-error/issues/8)
+  for noticing and to [`Igor Gnatenko`](https://gitlab.com/CreepySkeleton/proc-macro-error/-/merge_requests/25)
+  for fixing).
+
+# v0.4.10 (2020-2-29)
+
+* `proc-macro-error` doesn't depend on syn\[full\] anymore, the compilation
+  is \~30secs faster.
+
+# v0.4.9 (2020-2-13)
+
+* New function: `append_dummy`.
+
+# v0.4.8 (2020-2-01)
+
+* Support for children messages
+
+# v0.4.7 (2020-1-31)
+
+* Now any type that implements `quote::ToTokens` can be used instead of spans.
+  This allows for high quality error messages.
+
+# v0.4.6 (2020-1-31)
+
+* `From<syn::Error>` implementation doesn't lose span info anymore, see
+  [#6](https://gitlab.com/CreepySkeleton/proc-macro-error/issues/6).
+
+# v0.4.5 (2020-1-20)
+Just a small intermediate release.
+
+* Fix some bugs.
+* Populate license files into subfolders.
+
+# v0.4.4 (2019-11-13)
+* Fix `abort_if_dirty` + warnings bug
+* Allow trailing commas in macros
+
+# v0.4.2 (2019-11-7)
+* FINALLY fixed `__pme__suggestions not found` bug
+
+# v0.4.1 (2019-11-7) YANKED
+* Fixed `__pme__suggestions not found` bug
+* Documentation improvements, links checked
+
+# v0.4.0 (2019-11-6) YANKED
+
+## New features
+* "help" messages that can have their own span on nightly, they
+    inherit parent span on stable.
+    ```rust
+    let cond_help = if condition { Some("some help message") else { None } };
+    abort!(
+        span, // parent span
+        "something's wrong, {} wrongs in total", 10; // main message
+        help = "here's a help for you, {}", "take it"; // unconditional help message
+        help =? cond_help; // conditional help message, must be Option
+        note = note_span => "don't forget the note, {}", "would you?" // notes can have their own span but it's effective only on nightly
+    )
+    ```
+* Warnings via `emit_warning` and `emit_warning_call_site`. Nightly only, they're ignored on stable.
+* Now `proc-macro-error` delegates to `proc_macro::Diagnostic` on nightly.
+
+## Breaking changes
+* `MacroError` is now replaced by `Diagnostic`. Its API resembles `proc_macro::Diagnostic`.
+* `Diagnostic` does not implement `From<&str/String>` so `Result<T, &str/String>::abort_or_exit()`
+    won't work anymore (nobody used it anyway).
+* `macro_error!` macro is replaced with `diagnostic!`.
+
+## Improvements
+* Now `proc-macro-error` renders notes exactly just like rustc does.
+* We don't parse a body of a function annotated with `#[proc_macro_error]` anymore,
+  only looking at the signature. This should somewhat decrease expansion time for large functions.
+
+# v0.3.3 (2019-10-16)
+* Now you can use any word instead of "help", undocumented.
+
+# v0.3.2 (2019-10-16)
+* Introduced support for "help" messages, undocumented.
+
+# v0.3.0 (2019-10-8)
+
+## The crate has been completely rewritten from scratch!
+
+## Changes (most are breaking):
+* Renamed macros:
+  * `span_error` => `abort`
+  * `call_site_error` => `abort_call_site`
+* `filter_macro_errors` was replaced by `#[proc_macro_error]` attribute.
+* `set_dummy` now takes `TokenStream` instead of `Option<TokenStream>`
+* Support for multiple errors via `emit_error` and `emit_call_site_error`
+* New `macro_error` macro for building errors in format=like style.
+* `MacroError` API had been reconsidered. It also now implements `quote::ToTokens`.
+
+# v0.2.6 (2019-09-02)
+* Introduce support for dummy implementations via `dummy::set_dummy`
+* `multi::*` is now deprecated, will be completely rewritten in v0.3
+
+# v0.2.0 (2019-08-15)
+
+## Breaking changes
+* `trigger_error` replaced with `MacroError::trigger` and `filter_macro_error_panics`
+  is hidden from docs.
+  This is not quite a breaking change since users weren't supposed to use these functions directly anyway.
+* All dependencies are updated to `v1.*`.
+
+## New features
+* Ability to stack multiple errors via `multi::MultiMacroErrors` and emit them at once.
+
+## Improvements
+* Now `MacroError` implements `std::fmt::Display` instead of `std::string::ToString`.
+* `MacroError::span` inherent method.
+* `From<MacroError> for proc_macro/proc_macro2::TokenStream` implementations.
+* `AsRef/AsMut<String> for MacroError` implementations.
+
+# v0.1.x (2019-07-XX)
+
+## New features
+* An easy way to report errors inside within a proc-macro via `span_error`,
+  `call_site_error` and `filter_macro_errors`.
diff --git a/third-party/proc-macro-error2/Cargo.toml b/third-party/proc-macro-error2/Cargo.toml
new file mode 100644
index 0000000..f623e6c
--- /dev/null
+++ b/third-party/proc-macro-error2/Cargo.toml
@@ -0,0 +1,91 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2021"
+rust-version = "1.61"
+name = "proc-macro-error2"
+version = "2.0.1"
+authors = [
+    "CreepySkeleton <creepy-skeleton@yandex.ru>",
+    "GnomedDev <david2005thomas@gmail.com>",
+]
+build = false
+autobins = false
+autoexamples = false
+autotests = false
+autobenches = false
+description = "Almost drop-in replacement to panics in proc-macros"
+readme = "README.md"
+keywords = [
+    "proc-macro",
+    "error",
+    "errors",
+]
+categories = ["development-tools::procedural-macro-helpers"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/GnomedDev/proc-macro-error-2"
+
+[lib]
+name = "proc_macro_error2"
+path = "src/lib.rs"
+
+[[test]]
+name = "macro-errors"
+path = "tests/macro-errors.rs"
+
+[[test]]
+name = "ok"
+path = "tests/ok.rs"
+
+[[test]]
+name = "runtime-errors"
+path = "tests/runtime-errors.rs"
+
+[dependencies.proc-macro-error-attr2]
+version = "=2.0.0"
+
+[dependencies.proc-macro2]
+version = "1"
+
+[dependencies.quote]
+version = "1"
+
+[dependencies.syn]
+version = "2"
+optional = true
+default-features = false
+
+[dev-dependencies.syn]
+version = "2"
+features = ["full"]
+
+[dev-dependencies.trybuild]
+version = "1.0.99"
+features = ["diff"]
+
+[features]
+default = ["syn-error"]
+nightly = []
+syn-error = ["dep:syn"]
+
+[lints.clippy.module_name_repetitions]
+level = "allow"
+priority = 0
+
+[lints.clippy.pedantic]
+level = "warn"
+priority = -1
+
+[lints.rust.unexpected_cfgs]
+level = "warn"
+priority = 0
+check-cfg = ["cfg(run_ui_tests)"]
diff --git a/third-party/proc-macro-error2/Cargo.toml.orig b/third-party/proc-macro-error2/Cargo.toml.orig
new file mode 100644
index 0000000..fcc6161
--- /dev/null
+++ b/third-party/proc-macro-error2/Cargo.toml.orig
@@ -0,0 +1,41 @@
+[package]
+name = "proc-macro-error2"
+authors = [
+    "CreepySkeleton <creepy-skeleton@yandex.ru>",
+    "GnomedDev <david2005thomas@gmail.com>",
+]
+version = "2.0.1"
+description = "Almost drop-in replacement to panics in proc-macros"
+repository = "https://github.com/GnomedDev/proc-macro-error-2"
+rust-version = "1.61"
+keywords = ["proc-macro", "error", "errors"]
+categories = ["development-tools::procedural-macro-helpers"]
+license = "MIT OR Apache-2.0"
+edition = "2021"
+
+[dependencies]
+quote = "1"
+proc-macro2 = "1"
+proc-macro-error-attr2 = { path = "./proc-macro-error-attr", version = "=2.0.0" }
+
+[dependencies.syn]
+version = "2"
+optional = true
+default-features = false
+
+[dev-dependencies]
+test-crate = { path = "./test-crate" }
+syn = { version = "2", features = ["full"] }
+trybuild = { version = "1.0.99", features = ["diff"] }
+
+[features]
+default = ["syn-error"]
+syn-error = ["dep:syn"]
+nightly = []
+
+[lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = ['cfg(run_ui_tests)'] }
+
+[lints.clippy]
+pedantic = { level = "warn", priority = -1 }
+module_name_repetitions = { level = "allow" }
diff --git a/third-party/proc-macro-error2/LICENSE-APACHE b/third-party/proc-macro-error2/LICENSE-APACHE
new file mode 100644
index 0000000..658240a
--- /dev/null
+++ b/third-party/proc-macro-error2/LICENSE-APACHE
@@ -0,0 +1,201 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+   "License" shall mean the terms and conditions for use, reproduction,
+   and distribution as defined by Sections 1 through 9 of this document.
+
+   "Licensor" shall mean the copyright owner or entity authorized by
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+   "Legal Entity" shall mean the union of the acting entity and all
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+   "You" (or "Your") shall mean an individual or Legal Entity
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+   of this License, Derivative Works shall not include works that remain
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+   "Contributor" shall mean Licensor and any individual or Legal Entity
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+2. Grant of Copyright License. Subject to the terms and conditions of
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+4. Redistribution. You may reproduce and distribute copies of the
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+   You may add Your own copyright statement to Your modifications and
+   may provide additional or different license terms and conditions
+   for use, reproduction, or distribution of Your modifications, or
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+   reproduction, and distribution of the Work otherwise complies with
+   the conditions stated in this License.
+
+5. Submission of Contributions. Unless You explicitly state otherwise,
+   any Contribution intentionally submitted for inclusion in the Work
+   by You to the Licensor shall be under the terms and conditions of
+   this License, without any additional terms or conditions.
+   Notwithstanding the above, nothing herein shall supersede or modify
+   the terms of any separate license agreement you may have executed
+   with Licensor regarding such Contributions.
+
+6. Trademarks. This License does not grant permission to use the trade
+   names, trademarks, service marks, or product names of the Licensor,
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+   origin of the Work and reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty. Unless required by applicable law or
+   agreed to in writing, Licensor provides the Work (and each
+   Contributor provides its Contributions) on an "AS IS" BASIS,
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+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
+   unless required by applicable law (such as deliberate and grossly
+   negligent acts) or agreed to in writing, shall any Contributor be
+   liable to You for damages, including any direct, indirect, special,
+   incidental, or consequential damages of any character arising as a
+   result of this License or out of the use or inability to use the
+   Work (including but not limited to damages for loss of goodwill,
+   work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses), even if such Contributor
+   has been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability. While redistributing
+   the Work or Derivative Works thereof, You may choose to offer,
+   and charge a fee for, acceptance of support, warranty, indemnity,
+   or other liability obligations and/or rights consistent with this
+   License. However, in accepting such obligations, You may act only
+   on Your own behalf and on Your sole responsibility, not on behalf
+   of any other Contributor, and only if You agree to indemnify,
+   defend, and hold each Contributor harmless for any liability
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+   of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work.
+
+   To apply the Apache License to your work, attach the following
+   boilerplate notice, with the fields enclosed by brackets "[]"
+   replaced with your own identifying information. (Don't include
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+   file or class name and description of purpose be included on the
+   same "printed page" as the copyright notice for easier
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+
+Copyright 2019-2020 CreepySkeleton <creepy-skeleton@yandex.ru>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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diff --git a/third-party/proc-macro-error2/LICENSE-MIT b/third-party/proc-macro-error2/LICENSE-MIT
new file mode 100644
index 0000000..fc73e59
--- /dev/null
+++ b/third-party/proc-macro-error2/LICENSE-MIT
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2019-2020 CreepySkeleton
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/third-party/proc-macro-error2/README.md b/third-party/proc-macro-error2/README.md
new file mode 100644
index 0000000..0910eac
--- /dev/null
+++ b/third-party/proc-macro-error2/README.md
@@ -0,0 +1,250 @@
+# Makes error reporting in procedural macros nice and easy
+
+[![docs.rs](https://docs.rs/proc-macro-error2/badge.svg)](https://docs.rs/proc-macro-error2)
+[![unsafe forbidden](https://img.shields.io/badge/unsafe-forbidden-success.svg)](https://github.com/rust-secure-code/safety-dance/)
+
+This crate aims to make error reporting in proc-macros simple and easy to use.
+Migrate from `panic!`-based errors for as little effort as possible!
+
+Also, you can explicitly [append a dummy token stream][crate::dummy] to your errors.
+
+To achieve this, this crate serves as a tiny shim around `proc_macro::Diagnostic` and
+`compile_error!`. It detects the most preferable way to emit errors based on compiler's version.
+When the underlying diagnostic type is finally stabilized, this crate will be simply
+delegating to it, requiring no changes in your code!
+
+So you can just use this crate and have *both* some of `proc_macro::Diagnostic` functionality
+available on stable ahead of time and your error-reporting code future-proof.
+
+```toml
+[dependencies]
+proc-macro-error2 = "2.0"
+```
+
+*Supports rustc 1.61 and up*
+
+[Documentation and guide][guide]
+
+## Quick example
+
+Code:
+
+```rust
+#[proc_macro]
+#[proc_macro_error]
+pub fn make_fn(input: TokenStream) -> TokenStream {
+    let mut input = TokenStream2::from(input).into_iter();
+    let name = input.next().unwrap();
+    if let Some(second) = input.next() {
+        abort! { second,
+            "I don't like this part!";
+                note = "I see what you did there...";
+                help = "I need only one part, you know?";
+        }
+    }
+
+    quote!( fn #name() {} ).into()
+}
+```
+
+This is how the error is rendered in a terminal:
+
+<p align="center">
+<img src="https://user-images.githubusercontent.com/50968528/78830016-d3b46a80-79d6-11ea-9de2-972e8d7904ef.png" width="600">
+</p>
+
+And this is what your users will see in their IDE:
+
+<p align="center">
+<img src="https://user-images.githubusercontent.com/50968528/78830547-a9af7800-79d7-11ea-822e-59e29bda335c.png" width="600">
+</p>
+
+## Examples
+
+### Panic-like usage
+
+```rust
+use proc_macro_error2::{
+    proc_macro_error,
+    abort,
+    abort_call_site,
+    ResultExt,
+    OptionExt,
+};
+use proc_macro::TokenStream;
+use syn::{DeriveInput, parse_macro_input};
+use quote::quote;
+
+// This is your main entry point
+#[proc_macro]
+// This attribute *MUST* be placed on top of the #[proc_macro] function
+#[proc_macro_error]
+pub fn make_answer(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+
+    if let Err(err) = some_logic(&input) {
+        // we've got a span to blame, let's use it
+        // This immediately aborts the proc-macro and shows the error
+        //
+        // You can use `proc_macro::Span`, `proc_macro2::Span`, and
+        // anything that implements `quote::ToTokens` (almost every type from
+        // `syn` and `proc_macro2`)
+        abort!(err, "You made an error, go fix it: {}", err.msg);
+    }
+
+    // `Result` has some handy shortcuts if your error type implements
+    // `Into<Diagnostic>`. `Option` has one unconditionally.
+    more_logic(&input).expect_or_abort("What a careless user, behave!");
+
+    if !more_logic_for_logic_god(&input) {
+        // We don't have an exact location this time,
+        // so just highlight the proc-macro invocation itself
+        abort_call_site!(
+            "Bad, bad user! Now go stand in the corner and think about what you did!");
+    }
+
+    // Now all the processing is done, return `proc_macro::TokenStream`
+    quote!(/* stuff */).into()
+}
+```
+
+### `proc_macro::Diagnostic`-like usage
+
+```rust
+use proc_macro_error2::*;
+use proc_macro::TokenStream;
+use syn::{spanned::Spanned, DeriveInput, ItemStruct, Fields, Attribute , parse_macro_input};
+use quote::quote;
+
+fn process_attrs(attrs: &[Attribute]) -> Vec<Attribute> {
+    attrs
+        .iter()
+        .filter_map(|attr| match process_attr(attr) {
+            Ok(res) => Some(res),
+            Err(msg) => {
+                emit_error!(attr, "Invalid attribute: {}", msg);
+                None
+            }
+        })
+        .collect()
+}
+
+fn process_fields(_attrs: &Fields) -> Vec<TokenStream> {
+    // processing fields in pretty much the same way as attributes
+    unimplemented!()
+}
+
+#[proc_macro]
+#[proc_macro_error]
+pub fn make_answer(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as ItemStruct);
+    let attrs = process_attrs(&input.attrs);
+
+    // abort right now if some errors were encountered
+    // at the attributes processing stage
+    abort_if_dirty();
+
+    let fields = process_fields(&input.fields);
+
+    // no need to think about emitted errors
+    // #[proc_macro_error] will handle them for you
+    //
+    // just return a TokenStream as you normally would
+    quote!(/* stuff */).into()
+}
+```
+
+## Real world examples
+
+* [`structopt-derive`](https://github.com/TeXitoi/structopt/tree/master/structopt-derive)
+  (abort-like usage)
+* [`auto-impl`](https://github.com/auto-impl-rs/auto_impl/) (emit-like usage)
+
+## Limitations
+
+- Warnings are emitted only on nightly, they are ignored on stable.
+- "help" suggestions can't have their own span info on stable,
+  (essentially inheriting the parent span).
+- If your macro happens to trigger a panic, no errors will be displayed. This is not a
+  technical limitation but rather intentional design. `panic` is not for error reporting.
+
+## MSRV policy
+
+The MSRV is currently `1.61`, and this is considered a breaking change to increase.
+
+However, if an existing dependency requires a higher MSRV without a semver breaking update, this may be raised.
+
+## Motivation
+
+Error handling in proc-macros sucks. There's not much of a choice today:
+you either "bubble up" the error up to the top-level of the macro and convert it to
+a [`compile_error!`][compl_err] invocation or just use a good old panic. Both these ways suck:
+
+- Former sucks because it's quite redundant to unroll a proper error handling
+    just for critical errors that will crash the macro anyway; so people mostly
+    choose not to bother with it at all and use panic. Simple `.expect` is too tempting.
+
+    Also, if you do decide to implement this `Result`-based architecture in your macro
+    you're going to have to rewrite it entirely once [`proc_macro::Diagnostic`][] is finally
+    stable. Not cool.
+
+- Later sucks because there's no way to carry out the span info via `panic!`.
+    `rustc` will highlight the invocation itself but not some specific token inside it.
+
+    Furthermore, panics aren't for error-reporting at all; panics are for bug-detecting
+    (like unwrapping on `None` or out-of-range indexing) or for early development stages
+    when you need a prototype ASAP so error handling can wait. Mixing these usages only
+    messes things up.
+
+- There is [`proc_macro::Diagnostic`][] which is awesome but it has been experimental
+    for more than a year and is unlikely to be stabilized any time soon.
+
+    This crate's API is intentionally designed to be compatible with `proc_macro::Diagnostic`
+    and delegates to it whenever possible. Once `Diagnostics` is stable this crate
+    will **always** delegate to it, no code changes will be required on user side.
+
+That said, we need a solution, but this solution must meet these conditions:
+
+- It must be better than `panic!`. The main point: it must offer a way to carry the span information
+    over to user.
+- It must take as little effort as possible to migrate from `panic!`. Ideally, a new
+    macro with similar semantics plus ability to carry out span info.
+- It must maintain compatibility with [`proc_macro::Diagnostic`][] .
+- **It must be usable on stable**.
+
+This crate aims to provide such a mechanism. All you have to do is annotate your top-level
+`#[proc_macro]` function with `#[proc_macro_error]` attribute and change panics to
+[`abort!`]/[`abort_call_site!`] where appropriate, see [the Guide][guide].
+
+## Disclaimer
+Please note that **this crate is not intended to be used in any way other
+than error reporting in procedural macros**, use `Result` and `?` (possibly along with one of the
+many helpers out there) for anything else.
+
+<br>
+
+#### License
+
+<sup>
+Licensed under either of <a href="LICENSE-APACHE">Apache License, Version
+2.0</a> or <a href="LICENSE-MIT">MIT license</a> at your option.
+</sup>
+
+<br>
+
+<sub>
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
+be dual licensed as above, without any additional terms or conditions.
+</sub>
+
+
+[compl_err]: https://doc.rust-lang.org/std/macro.compile_error.html
+[`proc_macro::Diagnostic`]: https://doc.rust-lang.org/proc_macro/struct.Diagnostic.html
+
+[crate::dummy]: https://docs.rs/proc-macro-error2/1/proc_macro_error/dummy/index.html
+[crate::multi]: https://docs.rs/proc-macro-error2/1/proc_macro_error/multi/index.html
+
+[`abort_call_site!`]: https://docs.rs/proc-macro-error2/1/proc_macro_error/macro.abort_call_site.html
+[`abort!`]: https://docs.rs/proc-macro-error2/1/proc_macro_error/macro.abort.html
+[guide]: https://docs.rs/proc-macro-error2
diff --git a/third-party/proc-macro-error2/src/diagnostic.rs b/third-party/proc-macro-error2/src/diagnostic.rs
new file mode 100644
index 0000000..0455511
--- /dev/null
+++ b/third-party/proc-macro-error2/src/diagnostic.rs
@@ -0,0 +1,360 @@
+use crate::{abort_now, check_correctness, sealed::Sealed, SpanRange};
+use proc_macro2::Span;
+use proc_macro2::TokenStream;
+
+use quote::{quote_spanned, ToTokens};
+
+/// Represents a diagnostic level
+///
+/// # Warnings
+///
+/// Warnings are ignored on stable/beta
+#[derive(Debug, PartialEq)]
+#[non_exhaustive]
+pub enum Level {
+    Error,
+    Warning,
+}
+
+/// Represents a single diagnostic message
+#[derive(Debug)]
+#[must_use = "A diagnostic does nothing unless emitted"]
+pub struct Diagnostic {
+    pub(crate) level: Level,
+    pub(crate) span_range: SpanRange,
+    pub(crate) msg: String,
+    pub(crate) suggestions: Vec<(SuggestionKind, String, Option<SpanRange>)>,
+    pub(crate) children: Vec<(SpanRange, String)>,
+}
+
+/// A collection of methods that do not exist in `proc_macro::Diagnostic`
+/// but still useful to have around.
+///
+/// This trait is sealed and cannot be implemented outside of `proc_macro_error`.
+pub trait DiagnosticExt: Sealed {
+    /// Create a new diagnostic message that points to the `span_range`.
+    ///
+    /// This function is the same as `Diagnostic::spanned` but produces considerably
+    /// better error messages for multi-token spans on stable.
+    fn spanned_range(span_range: SpanRange, level: Level, message: String) -> Self;
+
+    /// Add another error message to self such that it will be emitted right after
+    /// the main message.
+    ///
+    /// This function is the same as `Diagnostic::span_error` but produces considerably
+    /// better error messages for multi-token spans on stable.
+    #[must_use]
+    fn span_range_error(self, span_range: SpanRange, msg: String) -> Self;
+
+    /// Attach a "help" note to your main message, the note will have it's own span on nightly.
+    ///
+    /// This function is the same as `Diagnostic::span_help` but produces considerably
+    /// better error messages for multi-token spans on stable.
+    ///
+    /// # Span
+    ///
+    /// The span is ignored on stable, the note effectively inherits its parent's (main message) span
+    #[must_use]
+    fn span_range_help(self, span_range: SpanRange, msg: String) -> Self;
+
+    /// Attach a note to your main message, the note will have it's own span on nightly.
+    ///
+    /// This function is the same as `Diagnostic::span_note` but produces considerably
+    /// better error messages for multi-token spans on stable.
+    ///
+    /// # Span
+    ///
+    /// The span is ignored on stable, the note effectively inherits its parent's (main message) span
+    #[must_use]
+    fn span_range_note(self, span_range: SpanRange, msg: String) -> Self;
+}
+
+impl DiagnosticExt for Diagnostic {
+    fn spanned_range(span_range: SpanRange, level: Level, message: String) -> Self {
+        Diagnostic {
+            level,
+            span_range,
+            msg: message,
+            suggestions: vec![],
+            children: vec![],
+        }
+    }
+
+    fn span_range_error(mut self, span_range: SpanRange, msg: String) -> Self {
+        self.children.push((span_range, msg));
+        self
+    }
+
+    fn span_range_help(mut self, span_range: SpanRange, msg: String) -> Self {
+        self.suggestions
+            .push((SuggestionKind::Help, msg, Some(span_range)));
+        self
+    }
+
+    fn span_range_note(mut self, span_range: SpanRange, msg: String) -> Self {
+        self.suggestions
+            .push((SuggestionKind::Note, msg, Some(span_range)));
+        self
+    }
+}
+
+impl Diagnostic {
+    /// Create a new diagnostic message that points to `Span::call_site()`
+    pub fn new(level: Level, message: String) -> Self {
+        Diagnostic::spanned(Span::call_site(), level, message)
+    }
+
+    /// Create a new diagnostic message that points to the `span`
+    pub fn spanned(span: Span, level: Level, message: String) -> Self {
+        Diagnostic::spanned_range(
+            SpanRange {
+                first: span,
+                last: span,
+            },
+            level,
+            message,
+        )
+    }
+
+    /// Add another error message to self such that it will be emitted right after
+    /// the main message.
+    pub fn span_error(self, span: Span, msg: String) -> Self {
+        self.span_range_error(
+            SpanRange {
+                first: span,
+                last: span,
+            },
+            msg,
+        )
+    }
+
+    /// Attach a "help" note to your main message, the note will have it's own span on nightly.
+    ///
+    /// # Span
+    ///
+    /// The span is ignored on stable, the note effectively inherits its parent's (main message) span
+    pub fn span_help(self, span: Span, msg: String) -> Self {
+        self.span_range_help(
+            SpanRange {
+                first: span,
+                last: span,
+            },
+            msg,
+        )
+    }
+
+    /// Attach a "help" note to your main message.
+    pub fn help(mut self, msg: String) -> Self {
+        self.suggestions.push((SuggestionKind::Help, msg, None));
+        self
+    }
+
+    /// Attach a note to your main message, the note will have it's own span on nightly.
+    ///
+    /// # Span
+    ///
+    /// The span is ignored on stable, the note effectively inherits its parent's (main message) span
+    pub fn span_note(self, span: Span, msg: String) -> Self {
+        self.span_range_note(
+            SpanRange {
+                first: span,
+                last: span,
+            },
+            msg,
+        )
+    }
+
+    /// Attach a note to your main message
+    pub fn note(mut self, msg: String) -> Self {
+        self.suggestions.push((SuggestionKind::Note, msg, None));
+        self
+    }
+
+    /// The message of main warning/error (no notes attached)
+    #[must_use]
+    pub fn message(&self) -> &str {
+        &self.msg
+    }
+
+    /// Abort the proc-macro's execution and display the diagnostic.
+    ///
+    /// # Warnings
+    ///
+    /// Warnings are not emitted on stable and beta, but this function will abort anyway.
+    pub fn abort(self) -> ! {
+        self.emit();
+        abort_now()
+    }
+
+    /// Display the diagnostic while not aborting macro execution.
+    ///
+    /// # Warnings
+    ///
+    /// Warnings are ignored on stable/beta
+    pub fn emit(self) {
+        check_correctness();
+        crate::imp::emit_diagnostic(self);
+    }
+}
+
+/// **NOT PUBLIC API! NOTHING TO SEE HERE!!!**
+#[doc(hidden)]
+impl Diagnostic {
+    pub fn span_suggestion(self, span: Span, suggestion: &str, msg: String) -> Self {
+        match suggestion {
+            "help" | "hint" => self.span_help(span, msg),
+            _ => self.span_note(span, msg),
+        }
+    }
+
+    pub fn suggestion(self, suggestion: &str, msg: String) -> Self {
+        match suggestion {
+            "help" | "hint" => self.help(msg),
+            _ => self.note(msg),
+        }
+    }
+}
+
+impl ToTokens for Diagnostic {
+    fn to_tokens(&self, ts: &mut TokenStream) {
+        use std::borrow::Cow;
+
+        fn ensure_lf(buf: &mut String, s: &str) {
+            if s.ends_with('\n') {
+                buf.push_str(s);
+            } else {
+                buf.push_str(s);
+                buf.push('\n');
+            }
+        }
+
+        fn diag_to_tokens(
+            span_range: SpanRange,
+            level: &Level,
+            msg: &str,
+            suggestions: &[(SuggestionKind, String, Option<SpanRange>)],
+        ) -> TokenStream {
+            if *level == Level::Warning {
+                return TokenStream::new();
+            }
+
+            let message = if suggestions.is_empty() {
+                Cow::Borrowed(msg)
+            } else {
+                let mut message = String::new();
+                ensure_lf(&mut message, msg);
+                message.push('\n');
+
+                for (kind, note, _span) in suggestions {
+                    message.push_str("  = ");
+                    message.push_str(kind.name());
+                    message.push_str(": ");
+                    ensure_lf(&mut message, note);
+                }
+                message.push('\n');
+
+                Cow::Owned(message)
+            };
+
+            let mut msg = proc_macro2::Literal::string(&message);
+            msg.set_span(span_range.last);
+            let group = quote_spanned!(span_range.last=> { #msg } );
+            quote_spanned!(span_range.first=> compile_error!#group)
+        }
+
+        ts.extend(diag_to_tokens(
+            self.span_range,
+            &self.level,
+            &self.msg,
+            &self.suggestions,
+        ));
+        ts.extend(
+            self.children
+                .iter()
+                .map(|(span_range, msg)| diag_to_tokens(*span_range, &Level::Error, msg, &[])),
+        );
+    }
+}
+
+#[derive(Debug)]
+pub(crate) enum SuggestionKind {
+    Help,
+    Note,
+}
+
+impl SuggestionKind {
+    fn name(&self) -> &'static str {
+        match self {
+            SuggestionKind::Note => "note",
+            SuggestionKind::Help => "help",
+        }
+    }
+}
+
+#[cfg(feature = "syn-error")]
+impl From<syn::Error> for Diagnostic {
+    fn from(err: syn::Error) -> Self {
+        use proc_macro2::{Delimiter, TokenTree};
+
+        fn gut_error(ts: &mut impl Iterator<Item = TokenTree>) -> Option<(SpanRange, String)> {
+            let start_span = ts.next()?.span();
+            ts.next().expect(":1");
+            ts.next().expect("core");
+            ts.next().expect(":2");
+            ts.next().expect(":3");
+            ts.next().expect("compile_error");
+            ts.next().expect("!");
+
+            let lit = match ts.next().unwrap() {
+                TokenTree::Group(group) => {
+                    // Currently `syn` builds `compile_error!` invocations
+                    // exclusively in `ident{"..."}` (braced) form which is not
+                    // followed by `;` (semicolon).
+                    //
+                    // But if it changes to `ident("...");` (parenthesized)
+                    // or `ident["..."];` (bracketed) form,
+                    // we will need to skip the `;` as well.
+                    // Highly unlikely, but better safe than sorry.
+
+                    if group.delimiter() == Delimiter::Parenthesis
+                        || group.delimiter() == Delimiter::Bracket
+                    {
+                        ts.next().unwrap(); // ;
+                    }
+
+                    match group.stream().into_iter().next().unwrap() {
+                        TokenTree::Literal(lit) => lit,
+                        _ => unreachable!(""),
+                    }
+                }
+                _ => unreachable!(""),
+            };
+
+            let last = lit.span();
+            let mut msg = lit.to_string();
+
+            // "abc" => abc
+            msg.pop();
+            msg.remove(0);
+
+            Some((
+                SpanRange {
+                    first: start_span,
+                    last,
+                },
+                msg,
+            ))
+        }
+
+        let mut ts = err.to_compile_error().into_iter();
+
+        let (span_range, msg) = gut_error(&mut ts).unwrap();
+        let mut res = Diagnostic::spanned_range(span_range, Level::Error, msg);
+
+        while let Some((span_range, msg)) = gut_error(&mut ts) {
+            res = res.span_range_error(span_range, msg);
+        }
+
+        res
+    }
+}
diff --git a/third-party/proc-macro-error2/src/dummy.rs b/third-party/proc-macro-error2/src/dummy.rs
new file mode 100644
index 0000000..5bc98bd
--- /dev/null
+++ b/third-party/proc-macro-error2/src/dummy.rs
@@ -0,0 +1,151 @@
+//! Facility to emit dummy implementations (or whatever) in case
+//! an error happen.
+//!
+//! `compile_error!` does not abort a compilation right away. This means
+//! `rustc` doesn't just show you the error and abort, it carries on the
+//! compilation process looking for other errors to report.
+//!
+//! Let's consider an example:
+//!
+//! ```rust,ignore
+//! use proc_macro::TokenStream;
+//! use proc_macro_error2::*;
+//!
+//! trait MyTrait {
+//!     fn do_thing();
+//! }
+//!
+//! // this proc macro is supposed to generate MyTrait impl
+//! #[proc_macro_derive(MyTrait)]
+//! #[proc_macro_error]
+//! fn example(input: TokenStream) -> TokenStream {
+//!     // somewhere deep inside
+//!     abort!(span, "something's wrong");
+//!
+//!     // this implementation will be generated if no error happened
+//!     quote! {
+//!         impl MyTrait for #name {
+//!             fn do_thing() {/* whatever */}
+//!         }
+//!     }
+//! }
+//!
+//! // ================
+//! // in main.rs
+//!
+//! // this derive triggers an error
+//! #[derive(MyTrait)] // first BOOM!
+//! struct Foo;
+//!
+//! fn main() {
+//!     Foo::do_thing(); // second BOOM!
+//! }
+//! ```
+//!
+//! The problem is: the generated token stream contains only `compile_error!`
+//! invocation, the impl was not generated. That means user will see two compilation
+//! errors:
+//!
+//! ```text
+//! error: something's wrong
+//!  --> $DIR/probe.rs:9:10
+//!   |
+//! 9 |#[proc_macro_derive(MyTrait)]
+//!   |                    ^^^^^^^
+//!
+//! error[E0599]: no function or associated item named `do_thing` found for type `Foo` in the current scope
+//!  --> src\main.rs:3:10
+//!   |
+//! 1 | struct Foo;
+//!   | ----------- function or associated item `do_thing` not found for this
+//! 2 | fn main() {
+//! 3 |     Foo::do_thing(); // second BOOM!
+//!   |          ^^^^^^^^ function or associated item not found in `Foo`
+//! ```
+//!
+//! But the second error is meaningless! We definitely need to fix this.
+//!
+//! Most used approach in cases like this is "dummy implementation" -
+//! omit `impl MyTrait for #name` and fill functions bodies with `unimplemented!()`.
+//!
+//! This is how you do it:
+//!
+//! ```rust,ignore
+//! use proc_macro::TokenStream;
+//! use proc_macro_error2::*;
+//!
+//!  trait MyTrait {
+//!      fn do_thing();
+//!  }
+//!
+//!  // this proc macro is supposed to generate MyTrait impl
+//!  #[proc_macro_derive(MyTrait)]
+//!  #[proc_macro_error]
+//!  fn example(input: TokenStream) -> TokenStream {
+//!      // first of all - we set a dummy impl which will be appended to
+//!      // `compile_error!` invocations in case a trigger does happen
+//!      set_dummy(quote! {
+//!          impl MyTrait for #name {
+//!              fn do_thing() { unimplemented!() }
+//!          }
+//!      });
+//!
+//!      // somewhere deep inside
+//!      abort!(span, "something's wrong");
+//!
+//!      // this implementation will be generated if no error happened
+//!      quote! {
+//!          impl MyTrait for #name {
+//!              fn do_thing() {/* whatever */}
+//!          }
+//!      }
+//!  }
+//!
+//!  // ================
+//!  // in main.rs
+//!
+//!  // this derive triggers an error
+//!  #[derive(MyTrait)] // first BOOM!
+//!  struct Foo;
+//!
+//!  fn main() {
+//!      Foo::do_thing(); // no more errors!
+//!  }
+//! ```
+
+use proc_macro2::TokenStream;
+use std::cell::RefCell;
+
+use crate::check_correctness;
+
+thread_local! {
+    static DUMMY_IMPL: RefCell<Option<TokenStream>> = const { RefCell::new(None) };
+}
+
+/// Sets dummy token stream which will be appended to `compile_error!(msg);...`
+/// invocations in case you'll emit any errors.
+///
+/// See [guide](../index.html#guide).
+#[allow(clippy::must_use_candidate)] // Mutates thread local state
+pub fn set_dummy(dummy: TokenStream) -> Option<TokenStream> {
+    check_correctness();
+    DUMMY_IMPL.with(|old_dummy| old_dummy.replace(Some(dummy)))
+}
+
+/// Same as [`set_dummy`] but, instead of resetting, appends tokens to the
+/// existing dummy (if any). Behaves as `set_dummy` if no dummy is present.
+pub fn append_dummy(dummy: TokenStream) {
+    check_correctness();
+    DUMMY_IMPL.with(|old_dummy| {
+        let mut cell = old_dummy.borrow_mut();
+        if let Some(ts) = cell.as_mut() {
+            ts.extend(dummy);
+        } else {
+            *cell = Some(dummy);
+        }
+    });
+}
+
+pub(crate) fn cleanup() -> Option<TokenStream> {
+    DUMMY_IMPL.with(|old_dummy| old_dummy.replace(None))
+}
diff --git a/third-party/proc-macro-error2/src/imp/delegate.rs b/third-party/proc-macro-error2/src/imp/delegate.rs
new file mode 100644
index 0000000..a3e6a80
--- /dev/null
+++ b/third-party/proc-macro-error2/src/imp/delegate.rs
@@ -0,0 +1,68 @@
+//! This implementation uses [`proc_macro::Diagnostic`], nightly only.
+
+use std::cell::Cell;
+
+use proc_macro::{Diagnostic as PDiag, Level as PLevel};
+
+use crate::{
+    abort_now, check_correctness,
+    diagnostic::{Diagnostic, Level, SuggestionKind},
+};
+
+pub fn abort_if_dirty() {
+    check_correctness();
+    if IS_DIRTY.with(|c| c.get()) {
+        abort_now()
+    }
+}
+
+pub(crate) fn cleanup() -> Vec<Diagnostic> {
+    IS_DIRTY.with(|c| c.set(false));
+    vec![]
+}
+
+pub(crate) fn emit_diagnostic(diag: Diagnostic) {
+    let Diagnostic {
+        level,
+        span_range,
+        msg,
+        suggestions,
+        children,
+    } = diag;
+
+    let span = span_range.collapse().unwrap();
+
+    let level = match level {
+        Level::Warning => PLevel::Warning,
+        Level::Error => {
+            IS_DIRTY.with(|c| c.set(true));
+            PLevel::Error
+        }
+    };
+
+    let mut res = PDiag::spanned(span, level, msg);
+
+    for (kind, msg, span) in suggestions {
+        res = match (kind, span) {
+            (SuggestionKind::Note, Some(span_range)) => {
+                res.span_note(span_range.collapse().unwrap(), msg)
+            }
+            (SuggestionKind::Help, Some(span_range)) => {
+                res.span_help(span_range.collapse().unwrap(), msg)
+            }
+            (SuggestionKind::Note, None) => res.note(msg),
+            (SuggestionKind::Help, None) => res.help(msg),
+        }
+    }
+
+    for (span_range, msg) in children {
+        let span = span_range.collapse().unwrap();
+        res = res.span_error(span, msg);
+    }
+
+    res.emit()
+}
+
+thread_local! {
+    static IS_DIRTY: Cell<bool> = Cell::new(false);
+}
diff --git a/third-party/proc-macro-error2/src/imp/fallback.rs b/third-party/proc-macro-error2/src/imp/fallback.rs
new file mode 100644
index 0000000..c10eb9a
--- /dev/null
+++ b/third-party/proc-macro-error2/src/imp/fallback.rs
@@ -0,0 +1,30 @@
+//! This implementation uses self-written stable facilities.
+
+use crate::{
+    abort_now, check_correctness,
+    diagnostic::{Diagnostic, Level},
+};
+use std::cell::RefCell;
+
+pub fn abort_if_dirty() {
+    check_correctness();
+    ERR_STORAGE.with(|storage| {
+        if !storage.borrow().is_empty() {
+            abort_now()
+        }
+    });
+}
+
+pub(crate) fn cleanup() -> Vec<Diagnostic> {
+    ERR_STORAGE.with(|storage| storage.replace(Vec::new()))
+}
+
+pub(crate) fn emit_diagnostic(diag: Diagnostic) {
+    if diag.level == Level::Error {
+        ERR_STORAGE.with(|storage| storage.borrow_mut().push(diag));
+    }
+}
+
+thread_local! {
+    static ERR_STORAGE: RefCell<Vec<Diagnostic>> = const { RefCell::new(Vec::new()) };
+}
diff --git a/third-party/proc-macro-error2/src/lib.rs b/third-party/proc-macro-error2/src/lib.rs
new file mode 100644
index 0000000..d496790
--- /dev/null
+++ b/third-party/proc-macro-error2/src/lib.rs
@@ -0,0 +1,565 @@
+//! # proc-macro-error2
+//!
+//! This crate aims to make error reporting in proc-macros simple and easy to use.
+//! Migrate from `panic!`-based errors for as little effort as possible!
+//!
+//! (Also, you can explicitly [append a dummy token stream](dummy/index.html) to your errors).
+//!
+//! To achieve his, this crate serves as a tiny shim around `proc_macro::Diagnostic` and
+//! `compile_error!`. It detects the best way of emitting available based on compiler's version.
+//! When the underlying diagnostic type is finally stabilized, this crate will simply be
+//! delegating to it requiring no changes in your code!
+//!
+//! So you can just use this crate and have *both* some of `proc_macro::Diagnostic` functionality
+//! available on stable ahead of time *and* your error-reporting code future-proof.
+//!
+//! ## Cargo features
+//!
+//! This crate provides *enabled by default* `syn-error` feature that gates
+//! `impl From<syn::Error> for Diagnostic` conversion. If you don't use `syn` and want
+//! to cut off some of compilation time, you can disable it via
+//!
+//! ```toml
+//! [dependencies]
+//! proc-macro-error2 = { version = "2.0.0", default-features = false }
+//! ```
+//!
+//! ***Please note that disabling this feature makes sense only if you don't depend on `syn`
+//! directly or indirectly, and you very likely do.**
+//!
+//! ## Real world examples
+//!
+//! * [`structopt-derive`](https://github.com/TeXitoi/structopt/tree/master/structopt-derive)
+//!   (abort-like usage)
+//! * [`auto-impl`](https://github.com/auto-impl-rs/auto_impl/) (emit-like usage)
+//!
+//! ## Limitations
+//!
+//! - Warnings are emitted only on nightly, they are ignored on stable.
+//! - "help" suggestions can't have their own span info on stable,
+//!   (essentially inheriting the parent span).
+//! - If a panic occurs somewhere in your macro no errors will be displayed. This is not a
+//!   technical limitation but rather intentional design. `panic` is not for error reporting.
+//!
+//! ### `#[proc_macro_error]` attribute
+//!
+//! **This attribute MUST be present on the top level of your macro** (the function
+//! annotated with any of `#[proc_macro]`, `#[proc_macro_derive]`, `#[proc_macro_attribute]`).
+//!
+//! This attribute performs the setup and cleanup necessary to make things work.
+//!
+//! In most cases you'll need the simple `#[proc_macro_error]` form without any
+//! additional settings. Feel free to [skip the "Syntax" section](#macros).
+//!
+//! #### Syntax
+//!
+//! `#[proc_macro_error]` or `#[proc_macro_error(settings...)]`, where `settings...`
+//! is a comma-separated list of:
+//!
+//! - `proc_macro_hack`:
+//!
+//!     In order to correctly cooperate with `#[proc_macro_hack]`, `#[proc_macro_error]`
+//!     attribute must be placed *before* (above) it, like this:
+//!
+//!     ```no_run
+//!     # use proc_macro2::TokenStream;
+//!     # const IGNORE: &str = "
+//!     #[proc_macro_error]
+//!     #[proc_macro_hack]
+//!     #[proc_macro]
+//!     # ";
+//!     fn my_macro(input: TokenStream) -> TokenStream {
+//!         unimplemented!()
+//!     }
+//!     ```
+//!
+//!     If, for some reason, you can't place it like that you can use
+//!     `#[proc_macro_error(proc_macro_hack)]` instead.
+//!
+//!     # Note
+//!
+//!     If `proc-macro-hack` was detected (by any means) `allow_not_macro`
+//!     and `assert_unwind_safe` will be applied automatically.
+//!
+//! - `allow_not_macro`:
+//!
+//!     By default, the attribute checks that it's applied to a proc-macro.
+//!     If none of `#[proc_macro]`, `#[proc_macro_derive]` nor `#[proc_macro_attribute]` are
+//!     present it will panic. It's the intention - this crate is supposed to be used only with
+//!     proc-macros.
+//!
+//!     This setting is made to bypass the check, useful in certain circumstances.
+//!
+//!     Pay attention: the function this attribute is applied to must return
+//!     `proc_macro::TokenStream`.
+//!
+//!     This setting is implied if `proc-macro-hack` was detected.
+//!
+//! - `assert_unwind_safe`:
+//!
+//!     By default, your code must be [unwind safe]. If your code is not unwind safe,
+//!     but you believe it's correct, you can use this setting to bypass the check.
+//!     You would need this for code that uses `lazy_static` or `thread_local` with
+//!     `Cell/RefCell` inside (and the like).
+//!
+//!     This setting is implied if `#[proc_macro_error]` is applied to a function
+//!     marked as `#[proc_macro]`, `#[proc_macro_derive]` or `#[proc_macro_attribute]`.
+//!
+//!     This setting is also implied if `proc-macro-hack` was detected.
+//!
+//! ## Macros
+//!
+//! Most of the time you want to use the macros. Syntax is described in the next section below.
+//!
+//! You'll need to decide how you want to emit errors:
+//!
+//! * Emit the error and abort. Very much panic-like usage. Served by [`abort!`] and
+//!   [`abort_call_site!`].
+//! * Emit the error but do not abort right away, looking for other errors to report.
+//!   Served by [`emit_error!`] and [`emit_call_site_error!`].
+//!
+//! You **can** mix these usages.
+//!
+//! `abort` and `emit_error` take a "source span" as the first argument. This source
+//! will be used to highlight the place the error originates from. It must be one of:
+//!
+//! * *Something* that implements [`ToTokens`] (most types in `syn` and `proc-macro2` do).
+//!   This source is the preferable one since it doesn't lose span information on multi-token
+//!   spans, see [this issue](https://gitlab.com/CreepySkeleton/proc-macro-error/-/issues/6)
+//!   for details.
+//! * [`proc_macro::Span`]
+//! * [`proc-macro2::Span`]
+//!
+//! The rest is your message in format-like style.
+//!
+//! See [the next section](#syntax-1) for detailed syntax.
+//!
+//! - [`abort!`]:
+//!
+//!     Very much panic-like usage - abort right away and show the error.
+//!     Expands to [`!`] (never type).
+//!
+//! - [`abort_call_site!`]:
+//!
+//!     Shortcut for `abort!(Span::call_site(), ...)`. Expands to [`!`] (never type).
+//!
+//! - [`emit_error!`]:
+//!
+//!     [`proc_macro::Diagnostic`]-like usage - emit the error but keep going,
+//!     looking for other errors to report.
+//!     The compilation will fail nonetheless. Expands to [`()`] (unit type).
+//!
+//! - [`emit_call_site_error!`]:
+//!
+//!     Shortcut for `emit_error!(Span::call_site(), ...)`. Expands to [`()`] (unit type).
+//!
+//! - [`emit_warning!`]:
+//!
+//!     Like `emit_error!` but emit a warning instead of error. The compilation won't fail
+//!     because of warnings.
+//!     Expands to [`()`] (unit type).
+//!
+//!     **Beware**: warnings are nightly only, they are completely ignored on stable.
+//!
+//! - [`emit_call_site_warning!`]:
+//!
+//!     Shortcut for `emit_warning!(Span::call_site(), ...)`. Expands to [`()`] (unit type).
+//!
+//! - [`diagnostic`]:
+//!
+//!     Build an instance of `Diagnostic` in format-like style.
+//!
+//! #### Syntax
+//!
+//! All the macros have pretty much the same syntax:
+//!
+//! 1.  ```ignore
+//!     abort!(single_expr)
+//!     ```
+//!     Shortcut for `Diagnostic::from(expr).abort()`.
+//!
+//! 2.  ```ignore
+//!     abort!(span, message)
+//!     ```
+//!     The first argument is an expression the span info should be taken from.
+//!
+//!     The second argument is the error message, it must implement [`ToString`].
+//!
+//! 3.  ```ignore
+//!     abort!(span, format_literal, format_args...)
+//!     ```
+//!
+//!     This form is pretty much the same as 2, except `format!(format_literal, format_args...)`
+//!     will be used to for the message instead of [`ToString`].
+//!
+//! That's it. `abort!`, `emit_warning`, `emit_error` share this exact syntax.
+//!
+//! `abort_call_site!`, `emit_call_site_warning`, `emit_call_site_error` lack 1 form
+//! and do not take span in 2'th and 3'th forms. Those are essentially shortcuts for
+//! `macro!(Span::call_site(), args...)`.
+//!
+//! `diagnostic!` requires a [`Level`] instance between `span` and second argument
+//! (1'th form is the same).
+//!
+//! > **Important!**
+//! >
+//! > If you have some type from `proc_macro` or `syn` to point to, do not call `.span()`
+//! > on it but rather use it directly:
+//! > ```no_run
+//! > # use proc_macro_error2::abort;
+//! > # let input = proc_macro2::TokenStream::new();
+//! > let ty: syn::Type = syn::parse2(input).unwrap();
+//! > abort!(ty, "BOOM");
+//! > //     ^^ <-- avoid .span()
+//! > ```
+//! >
+//! > `.span()` calls work too, but you may experience regressions in message quality.
+//!
+//! #### Note attachments
+//!
+//! 3.  Every macro can have "note" attachments (only 2 and 3 form).
+//!   ```ignore
+//!   let opt_help = if have_some_info { Some("did you mean `this`?") } else { None };
+//!
+//!   abort!(
+//!       span, message; // <--- attachments start with `;` (semicolon)
+//!
+//!       help = "format {} {}", "arg1", "arg2"; // <--- every attachment ends with `;`,
+//!                                              //      maybe except the last one
+//!
+//!       note = "to_string"; // <--- one arg uses `.to_string()` instead of `format!()`
+//!
+//!       yay = "I see what {} did here", "you"; // <--- "help =" and "hint =" are mapped
+//!                                              // to Diagnostic::help,
+//!                                              // anything else is Diagnostic::note
+//!
+//!       wow = note_span => "custom span"; // <--- attachments can have their own span
+//!                                         //      it takes effect only on nightly though
+//!
+//!       hint =? opt_help; // <-- "optional" attachment, get displayed only if `Some`
+//!                         //     must be single `Option` expression
+//!
+//!       note =? note_span => opt_help // <-- optional attachments can have custom spans too
+//!   );
+//!   ```
+//!
+
+//! ### Diagnostic type
+//!
+//! [`Diagnostic`] type is intentionally designed to be API compatible with [`proc_macro::Diagnostic`].
+//! Not all API is implemented, only the part that can be reasonably implemented on stable.
+//!
+//!
+//! [`abort!`]: macro.abort.html
+//! [`abort_call_site!`]: macro.abort_call_site.html
+//! [`emit_warning!`]: macro.emit_warning.html
+//! [`emit_error!`]: macro.emit_error.html
+//! [`emit_call_site_warning!`]: macro.emit_call_site_error.html
+//! [`emit_call_site_error!`]: macro.emit_call_site_warning.html
+//! [`diagnostic!`]: macro.diagnostic.html
+//! [`Diagnostic`]: struct.Diagnostic.html
+//!
+//! [`proc_macro::Span`]: https://doc.rust-lang.org/proc_macro/struct.Span.html
+//! [`proc_macro::Diagnostic`]: https://doc.rust-lang.org/proc_macro/struct.Diagnostic.html
+//!
+//! [unwind safe]: https://doc.rust-lang.org/std/panic/trait.UnwindSafe.html#what-is-unwind-safety
+//! [`!`]: https://doc.rust-lang.org/std/primitive.never.html
+//! [`()`]: https://doc.rust-lang.org/std/primitive.unit.html
+//! [`ToString`]: https://doc.rust-lang.org/std/string/trait.ToString.html
+//!
+//! [`proc-macro2::Span`]: https://docs.rs/proc-macro2/1.0.10/proc_macro2/struct.Span.html
+//! [`ToTokens`]: https://docs.rs/quote/1.0.3/quote/trait.ToTokens.html
+//!
+
+#![cfg_attr(feature = "nightly", feature(proc_macro_diagnostic))]
+#![forbid(unsafe_code)]
+
+pub extern crate proc_macro;
+
+pub use crate::{
+    diagnostic::{Diagnostic, DiagnosticExt, Level},
+    dummy::{append_dummy, set_dummy},
+};
+pub use proc_macro_error_attr2::proc_macro_error;
+
+use proc_macro2::Span;
+use quote::{quote, ToTokens};
+
+use std::cell::Cell;
+use std::panic::{catch_unwind, resume_unwind, UnwindSafe};
+
+pub mod dummy;
+
+mod diagnostic;
+mod macros;
+mod sealed;
+
+#[cfg(not(feature = "nightly"))]
+#[path = "imp/fallback.rs"]
+mod imp;
+
+#[cfg(feature = "nightly")]
+#[path = "imp/delegate.rs"]
+mod imp;
+
+#[derive(Debug, Clone, Copy)]
+#[must_use = "A SpanRange does nothing unless used"]
+pub struct SpanRange {
+    pub first: Span,
+    pub last: Span,
+}
+
+impl SpanRange {
+    /// Create a range with the `first` and `last` spans being the same.
+    pub fn single_span(span: Span) -> Self {
+        SpanRange {
+            first: span,
+            last: span,
+        }
+    }
+
+    /// Create a `SpanRange` resolving at call site.
+    pub fn call_site() -> Self {
+        SpanRange::single_span(Span::call_site())
+    }
+
+    /// Construct span range from a `TokenStream`. This method always preserves all the
+    /// range.
+    ///
+    /// ### Note
+    ///
+    /// If the stream is empty, the result is `SpanRange::call_site()`. If the stream
+    /// consists of only one `TokenTree`, the result is `SpanRange::single_span(tt.span())`
+    /// that doesn't lose anything.
+    pub fn from_tokens(ts: &dyn ToTokens) -> Self {
+        let mut spans = ts.to_token_stream().into_iter().map(|tt| tt.span());
+        let first = spans.next().unwrap_or_else(Span::call_site);
+        let last = spans.last().unwrap_or(first);
+
+        SpanRange { first, last }
+    }
+
+    /// Join two span ranges. The resulting range will start at `self.first` and end at
+    /// `other.last`.
+    pub fn join_range(self, other: SpanRange) -> Self {
+        SpanRange {
+            first: self.first,
+            last: other.last,
+        }
+    }
+
+    /// Collapse the range into single span, preserving as much information as possible.
+    #[must_use]
+    pub fn collapse(self) -> Span {
+        self.first.join(self.last).unwrap_or(self.first)
+    }
+}
+
+/// This traits expands `Result<T, Into<Diagnostic>>` with some handy shortcuts.
+pub trait ResultExt {
+    type Ok;
+
+    /// Behaves like `Result::unwrap`: if self is `Ok` yield the contained value,
+    /// otherwise abort macro execution via `abort!`.
+    fn unwrap_or_abort(self) -> Self::Ok;
+
+    /// Behaves like `Result::expect`: if self is `Ok` yield the contained value,
+    /// otherwise abort macro execution via `abort!`.
+    /// If it aborts then resulting error message will be preceded with `message`.
+    fn expect_or_abort(self, msg: &str) -> Self::Ok;
+}
+
+/// This traits expands `Option` with some handy shortcuts.
+pub trait OptionExt {
+    type Some;
+
+    /// Behaves like `Option::expect`: if self is `Some` yield the contained value,
+    /// otherwise abort macro execution via `abort_call_site!`.
+    /// If it aborts the `message` will be used for [`compile_error!`][compl_err] invocation.
+    ///
+    /// [compl_err]: https://doc.rust-lang.org/std/macro.compile_error.html
+    fn expect_or_abort(self, msg: &str) -> Self::Some;
+}
+
+/// Abort macro execution and display all the emitted errors, if any.
+///
+/// Does nothing if no errors were emitted (warnings do not count).
+pub fn abort_if_dirty() {
+    imp::abort_if_dirty();
+}
+
+impl<T, E: Into<Diagnostic>> ResultExt for Result<T, E> {
+    type Ok = T;
+
+    fn unwrap_or_abort(self) -> T {
+        match self {
+            Ok(res) => res,
+            Err(e) => e.into().abort(),
+        }
+    }
+
+    fn expect_or_abort(self, message: &str) -> T {
+        match self {
+            Ok(res) => res,
+            Err(e) => {
+                let mut e = e.into();
+                e.msg = format!("{}: {}", message, e.msg);
+                e.abort()
+            }
+        }
+    }
+}
+
+impl<T> OptionExt for Option<T> {
+    type Some = T;
+
+    fn expect_or_abort(self, message: &str) -> T {
+        match self {
+            Some(res) => res,
+            None => abort_call_site!(message),
+        }
+    }
+}
+
+/// This is the entry point for a proc-macro.
+///
+/// **NOT PUBLIC API, SUBJECT TO CHANGE WITHOUT ANY NOTICE**
+#[doc(hidden)]
+pub fn entry_point<F>(f: F, proc_macro_hack: bool) -> proc_macro::TokenStream
+where
+    F: FnOnce() -> proc_macro::TokenStream + UnwindSafe,
+{
+    ENTERED_ENTRY_POINT.with(|flag| flag.set(flag.get() + 1));
+    let caught = catch_unwind(f);
+    let dummy = dummy::cleanup();
+    let err_storage = imp::cleanup();
+    ENTERED_ENTRY_POINT.with(|flag| flag.set(flag.get() - 1));
+
+    let gen_error = || {
+        if proc_macro_hack {
+            quote! {{
+                macro_rules! proc_macro_call {
+                    () => ( unimplemented!() )
+                }
+
+                #(#err_storage)*
+                #dummy
+
+                unimplemented!()
+            }}
+        } else {
+            quote!( #(#err_storage)* #dummy )
+        }
+    };
+
+    match caught {
+        Ok(ts) => {
+            if err_storage.is_empty() {
+                ts
+            } else {
+                gen_error().into()
+            }
+        }
+
+        Err(boxed) => match boxed.downcast::<AbortNow>() {
+            Ok(_) => gen_error().into(),
+            Err(boxed) => resume_unwind(boxed),
+        },
+    }
+}
+
+fn abort_now() -> ! {
+    check_correctness();
+    std::panic::panic_any(AbortNow)
+}
+
+thread_local! {
+    static ENTERED_ENTRY_POINT: Cell<usize> = const { Cell::new(0) };
+}
+
+struct AbortNow;
+
+fn check_correctness() {
+    assert!(
+        ENTERED_ENTRY_POINT.with(Cell::get) != 0,
+        "proc-macro-error2 API cannot be used outside of `entry_point` invocation, \
+             perhaps you forgot to annotate your #[proc_macro] function with `#[proc_macro_error]"
+    );
+}
+
+/// **ALL THE STUFF INSIDE IS NOT PUBLIC API!!!**
+#[doc(hidden)]
+pub mod __export {
+    // reexports for use in macros
+    pub use proc_macro;
+    pub use proc_macro2;
+
+    use proc_macro2::Span;
+    use quote::ToTokens;
+
+    use crate::SpanRange;
+
+    // inspired by
+    // https://github.com/dtolnay/case-studies/blob/master/autoref-specialization/README.md#simple-application
+
+    pub trait SpanAsSpanRange {
+        #[allow(non_snake_case)]
+        fn FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange(&self) -> SpanRange;
+    }
+
+    pub trait Span2AsSpanRange {
+        #[allow(non_snake_case)]
+        fn FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange(&self) -> SpanRange;
+    }
+
+    pub trait ToTokensAsSpanRange {
+        #[allow(non_snake_case)]
+        fn FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange(&self) -> SpanRange;
+    }
+
+    pub trait SpanRangeAsSpanRange {
+        #[allow(non_snake_case)]
+        fn FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange(&self) -> SpanRange;
+    }
+
+    impl<T: ToTokens> ToTokensAsSpanRange for &T {
+        fn FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange(&self) -> SpanRange {
+            let mut ts = self.to_token_stream().into_iter();
+            let first = match ts.next() {
+                Some(t) => t.span(),
+                None => Span::call_site(),
+            };
+
+            let last = match ts.last() {
+                Some(t) => t.span(),
+                None => first,
+            };
+
+            SpanRange { first, last }
+        }
+    }
+
+    impl Span2AsSpanRange for Span {
+        fn FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange(&self) -> SpanRange {
+            SpanRange {
+                first: *self,
+                last: *self,
+            }
+        }
+    }
+
+    impl SpanAsSpanRange for proc_macro::Span {
+        fn FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange(&self) -> SpanRange {
+            SpanRange {
+                first: (*self).into(),
+                last: (*self).into(),
+            }
+        }
+    }
+
+    impl SpanRangeAsSpanRange for SpanRange {
+        fn FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange(&self) -> SpanRange {
+            *self
+        }
+    }
+}
diff --git a/third-party/proc-macro-error2/src/macros.rs b/third-party/proc-macro-error2/src/macros.rs
new file mode 100644
index 0000000..747b684
--- /dev/null
+++ b/third-party/proc-macro-error2/src/macros.rs
@@ -0,0 +1,288 @@
+// FIXME: this can be greatly simplified via $()?
+// as soon as MRSV hits 1.32
+
+/// Build [`Diagnostic`](struct.Diagnostic.html) instance from provided arguments.
+///
+/// # Syntax
+///
+/// See [the guide](index.html#guide).
+///
+#[macro_export]
+macro_rules! diagnostic {
+    // from alias
+    ($err:expr) => { $crate::Diagnostic::from($err) };
+
+    // span, message, help
+    ($span:expr, $level:expr, $fmt:expr, $($args:expr),+ ; $($rest:tt)+) => {{
+        #[allow(unused_imports)]
+        use $crate::__export::{
+            ToTokensAsSpanRange,
+            Span2AsSpanRange,
+            SpanAsSpanRange,
+            SpanRangeAsSpanRange
+        };
+        use $crate::DiagnosticExt;
+        let span_range = (&$span).FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange();
+
+        let diag = $crate::Diagnostic::spanned_range(
+            span_range,
+            $level,
+            format!($fmt, $($args),*)
+        );
+        $crate::__pme__suggestions!(diag $($rest)*);
+        diag
+    }};
+
+    ($span:expr, $level:expr, $msg:expr ; $($rest:tt)+) => {{
+        #[allow(unused_imports)]
+        use $crate::__export::{
+            ToTokensAsSpanRange,
+            Span2AsSpanRange,
+            SpanAsSpanRange,
+            SpanRangeAsSpanRange
+        };
+        use $crate::DiagnosticExt;
+        let span_range = (&$span).FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange();
+
+        let diag = $crate::Diagnostic::spanned_range(span_range, $level, $msg.to_string());
+        $crate::__pme__suggestions!(diag $($rest)*);
+        diag
+    }};
+
+    // span, message, no help
+    ($span:expr, $level:expr, $fmt:expr, $($args:expr),+) => {{
+        #[allow(unused_imports)]
+        use $crate::__export::{
+            ToTokensAsSpanRange,
+            Span2AsSpanRange,
+            SpanAsSpanRange,
+            SpanRangeAsSpanRange
+        };
+        use $crate::DiagnosticExt;
+        let span_range = (&$span).FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange();
+
+        $crate::Diagnostic::spanned_range(
+            span_range,
+            $level,
+            format!($fmt, $($args),*)
+        )
+    }};
+
+    ($span:expr, $level:expr, $msg:expr) => {{
+        #[allow(unused_imports)]
+        use $crate::__export::{
+            ToTokensAsSpanRange,
+            Span2AsSpanRange,
+            SpanAsSpanRange,
+            SpanRangeAsSpanRange
+        };
+        use $crate::DiagnosticExt;
+        let span_range = (&$span).FIRST_ARG_MUST_EITHER_BE_Span_OR_IMPLEMENT_ToTokens_OR_BE_SpanRange();
+
+        $crate::Diagnostic::spanned_range(span_range, $level, $msg.to_string())
+    }};
+
+
+    // trailing commas
+
+    ($span:expr, $level:expr, $fmt:expr, $($args:expr),+, ; $($rest:tt)+) => {
+        $crate::diagnostic!($span, $level, $fmt, $($args),* ; $($rest)*)
+    };
+    ($span:expr, $level:expr, $msg:expr, ; $($rest:tt)+) => {
+        $crate::diagnostic!($span, $level, $msg ; $($rest)*)
+    };
+    ($span:expr, $level:expr, $fmt:expr, $($args:expr),+,) => {
+        $crate::diagnostic!($span, $level, $fmt, $($args),*)
+    };
+    ($span:expr, $level:expr, $msg:expr,) => {
+        $crate::diagnostic!($span, $level, $msg)
+    };
+    // ($err:expr,) => { $crate::diagnostic!($err) };
+}
+
+/// Abort proc-macro execution right now and display the error.
+///
+/// # Syntax
+///
+/// See [the guide](index.html#guide).
+#[macro_export]
+macro_rules! abort {
+    ($err:expr) => {
+        $crate::diagnostic!($err).abort()
+    };
+
+    ($span:expr, $($tts:tt)*) => {
+        $crate::diagnostic!($span, $crate::Level::Error, $($tts)*).abort()
+    };
+}
+
+/// Shortcut for `abort!(Span::call_site(), msg...)`. This macro
+/// is still preferable over plain panic, panics are not for error reporting.
+///
+/// # Syntax
+///
+/// See [the guide](index.html#guide).
+///
+#[macro_export]
+macro_rules! abort_call_site {
+    ($($tts:tt)*) => {
+        $crate::abort!($crate::__export::proc_macro2::Span::call_site(), $($tts)*)
+    };
+}
+
+/// Emit an error while not aborting the proc-macro right away.
+///
+/// # Syntax
+///
+/// See [the guide](index.html#guide).
+///
+#[macro_export]
+macro_rules! emit_error {
+    ($err:expr) => {
+        $crate::diagnostic!($err).emit()
+    };
+
+    ($span:expr, $($tts:tt)*) => {{
+        let level = $crate::Level::Error;
+        $crate::diagnostic!($span, level, $($tts)*).emit()
+    }};
+}
+
+/// Shortcut for `emit_error!(Span::call_site(), ...)`. This macro
+/// is still preferable over plain panic, panics are not for error reporting..
+///
+/// # Syntax
+///
+/// See [the guide](index.html#guide).
+///
+#[macro_export]
+macro_rules! emit_call_site_error {
+    ($($tts:tt)*) => {
+        $crate::emit_error!($crate::__export::proc_macro2::Span::call_site(), $($tts)*)
+    };
+}
+
+/// Emit a warning. Warnings are not errors and compilation won't fail because of them.
+///
+/// **Does nothing on stable**
+///
+/// # Syntax
+///
+/// See [the guide](index.html#guide).
+///
+#[macro_export]
+macro_rules! emit_warning {
+    ($span:expr, $($tts:tt)*) => {
+        $crate::diagnostic!($span, $crate::Level::Warning, $($tts)*).emit()
+    };
+}
+
+/// Shortcut for `emit_warning!(Span::call_site(), ...)`.
+///
+/// **Does nothing on stable**
+///
+/// # Syntax
+///
+/// See [the guide](index.html#guide).
+///
+#[macro_export]
+macro_rules! emit_call_site_warning {
+    ($($tts:tt)*) => {{
+        $crate::emit_warning!($crate::__export::proc_macro2::Span::call_site(), $($tts)*)
+    }};
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pme__suggestions {
+    ($var:ident) => ();
+
+    ($var:ident $help:ident =? $msg:expr) => {
+        let $var = if let Some(msg) = $msg {
+            $var.suggestion(stringify!($help), msg.to_string())
+        } else {
+            $var
+        };
+    };
+    ($var:ident $help:ident =? $span:expr => $msg:expr) => {
+        let $var = if let Some(msg) = $msg {
+            $var.span_suggestion($span.into(), stringify!($help), msg.to_string())
+        } else {
+            $var
+        };
+    };
+
+    ($var:ident $help:ident =? $msg:expr ; $($rest:tt)*) => {
+        $crate::__pme__suggestions!($var $help =? $msg);
+        $crate::__pme__suggestions!($var $($rest)*);
+    };
+    ($var:ident $help:ident =? $span:expr => $msg:expr ; $($rest:tt)*) => {
+        $crate::__pme__suggestions!($var $help =? $span => $msg);
+        $crate::__pme__suggestions!($var $($rest)*);
+    };
+
+
+    ($var:ident $help:ident = $msg:expr) => {
+        let $var = $var.suggestion(stringify!($help), $msg.to_string());
+    };
+    ($var:ident $help:ident = $fmt:expr, $($args:expr),+) => {
+        let $var = $var.suggestion(
+            stringify!($help),
+            format!($fmt, $($args),*)
+        );
+    };
+    ($var:ident $help:ident = $span:expr => $msg:expr) => {
+        let $var = $var.span_suggestion($span.into(), stringify!($help), $msg.to_string());
+    };
+    ($var:ident $help:ident = $span:expr => $fmt:expr, $($args:expr),+) => {
+        let $var = $var.span_suggestion(
+            $span.into(),
+            stringify!($help),
+            format!($fmt, $($args),*)
+        );
+    };
+
+    ($var:ident $help:ident = $msg:expr ; $($rest:tt)*) => {
+        $crate::__pme__suggestions!($var $help = $msg);
+        $crate::__pme__suggestions!($var $($rest)*);
+    };
+    ($var:ident $help:ident = $fmt:expr, $($args:expr),+ ; $($rest:tt)*) => {
+        $crate::__pme__suggestions!($var $help = $fmt, $($args),*);
+        $crate::__pme__suggestions!($var $($rest)*);
+    };
+    ($var:ident $help:ident = $span:expr => $msg:expr ; $($rest:tt)*) => {
+        $crate::__pme__suggestions!($var $help = $span => $msg);
+        $crate::__pme__suggestions!($var $($rest)*);
+    };
+    ($var:ident $help:ident = $span:expr => $fmt:expr, $($args:expr),+ ; $($rest:tt)*) => {
+        $crate::__pme__suggestions!($var $help = $span => $fmt, $($args),*);
+        $crate::__pme__suggestions!($var $($rest)*);
+    };
+
+    // trailing commas
+
+    ($var:ident $help:ident = $msg:expr,) => {
+        $crate::__pme__suggestions!($var $help = $msg)
+    };
+    ($var:ident $help:ident = $fmt:expr, $($args:expr),+,) => {
+        $crate::__pme__suggestions!($var $help = $fmt, $($args)*)
+    };
+    ($var:ident $help:ident = $span:expr => $msg:expr,) => {
+        $crate::__pme__suggestions!($var $help = $span => $msg)
+    };
+    ($var:ident $help:ident = $span:expr => $fmt:expr, $($args:expr),*,) => {
+        $crate::__pme__suggestions!($var $help = $span => $fmt, $($args)*)
+    };
+    ($var:ident $help:ident = $msg:expr, ; $($rest:tt)*) => {
+        $crate::__pme__suggestions!($var $help = $msg; $($rest)*)
+    };
+    ($var:ident $help:ident = $fmt:expr, $($args:expr),+, ; $($rest:tt)*) => {
+        $crate::__pme__suggestions!($var $help = $fmt, $($args),*; $($rest)*)
+    };
+    ($var:ident $help:ident = $span:expr => $msg:expr, ; $($rest:tt)*) => {
+        $crate::__pme__suggestions!($var $help = $span => $msg; $($rest)*)
+    };
+    ($var:ident $help:ident = $span:expr => $fmt:expr, $($args:expr),+, ; $($rest:tt)*) => {
+        $crate::__pme__suggestions!($var $help = $span => $fmt, $($args),*; $($rest)*)
+    };
+}
diff --git a/third-party/proc-macro-error2/src/sealed.rs b/third-party/proc-macro-error2/src/sealed.rs
new file mode 100644
index 0000000..a2d5081
--- /dev/null
+++ b/third-party/proc-macro-error2/src/sealed.rs
@@ -0,0 +1,3 @@
+pub trait Sealed {}
+
+impl Sealed for crate::Diagnostic {}