fix(mcu): honor AVR PlatformIO registry pins

crates/fbuild-build-engine/src/package_override.rs

@@ -578,6 +578,45 @@ mod tests {
         }
     }
 
+    #[test]
+    fn pinned_megaavr_tiny_core_selects_newer_avr_toolchain() {
+        let manifest = r#"{"packages":{"framework-arduino-megaavr-megatinycore":{"type":"framework","owner":"platformio","version":"~2.6.11","optional":true},"toolchain-atmelavr":{"type":"toolchain","owner":"platformio","version":"~1.70300.0","optionalVersions":["~3.70300.0"]}}}"#;
+        let builder = "        if build_core in (\"megatinycore\", \"dxcore\"):\n            self.packages[\"toolchain-atmelavr\"][\"version\"] = \"~3.70300.0\"\n";
+        let defaults = [(
+            "toolchain-atmelavr",
+            PlatformDefaultVersion::BuilderBranch {
+                marker: "if build_core in (\"megatinycore\", \"dxcore\"):",
+                after: None,
+            },
+        )];
+        let requirements =
+            requirements_with_platform_defaults(manifest, Some(builder), &[], &defaults).unwrap();
+        assert_eq!(
+            require_platform_package(&requirements, "toolchain-atmelavr")
+                .unwrap()
+                .spec
+                .registry()
+                .unwrap()
+                .requirement
+                .as_deref(),
+            Some("~3.70300.0")
+        );
+        let explicit = parse_package_spec("toolchain-atmelavr@1.70300.191015").unwrap();
+        let requirements =
+            requirements_with_platform_defaults(manifest, Some(builder), &[explicit], &defaults)
+                .unwrap();
+        assert_eq!(
+            require_platform_package(&requirements, "toolchain-atmelavr")
+                .unwrap()
+                .spec
+                .registry()
+                .unwrap()
+                .requirement
+                .as_deref(),
+            Some("1.70300.191015")
+        );
+    }
+
     #[test]
     fn pinned_sam_builder_selects_adafruit_gcc_and_rejects_changed_rule() {
         let builder = "    if build_core == \"adafruit\":\n        self.packages[\"toolchain-gccarmnoneeabi\"][\"version\"] = \"~1.90301.0\"\n";

crates/fbuild-build-engine/src/pipeline/context.rs

@@ -186,6 +186,10 @@ impl BuildContext {
                 Some(fbuild_core::Platform::RaspberryPi) => {
                     Some(fbuild_core::Platform::RaspberryPi)
                 }
+                Some(fbuild_core::Platform::AtmelAvr) => Some(fbuild_core::Platform::AtmelAvr),
+                Some(fbuild_core::Platform::AtmelMegaAvr) => {
+                    Some(fbuild_core::Platform::AtmelMegaAvr)
+                }
                 _ => None,
             };
             let resolved_packages: &[&str] = match resolved_platform {
@@ -231,6 +235,29 @@ impl BuildContext {
                     "toolchain-rp2040-earlephilhower",
                     "tool-picotool-rp2040-earlephilhower",
                 ],
+                Some(fbuild_core::Platform::AtmelAvr) => &[
+                    "framework-arduino-avr",
+                    "framework-arduino-avr-attiny",
+                    "framework-arduino-avr-digistump",
+                    "framework-arduino-avr-minicore",
+                    "framework-arduino-avr-majorcore",
+                    "framework-arduino-avr-megacore",
+                    "framework-arduino-avr-microcore",
+                    "framework-arduino-avr-mightycore",
+                    "framework-arduino-avr-bean",
+                    "framework-arduino-avr-dwenguino",
+                    "framework-arduino-avr-nicai",
+                    "framework-arduino-avr-panstamp",
+                    "framework-arduino-avr-prusa_rambo",
+                    "toolchain-atmelavr",
+                ],
+                Some(fbuild_core::Platform::AtmelMegaAvr) => &[
+                    "framework-arduino-megaavr",
+                    "framework-arduino-megaavr-megacorex",
+                    "framework-arduino-megaavr-megatinycore",
+                    "framework-arduino-megaavr-dxcore",
+                    "toolchain-atmelavr",
+                ],
                 _ => &[],
             };
             for warning in fbuild_config::ignored_version_pins_with_resolved_packages(

crates/fbuild-build-mcu/src/avr/mod.rs

@@ -25,7 +25,8 @@ impl crate::PlatformSupport for AvrPlatformSupport {
     ) -> fbuild_core::Result<Vec<crate::provision::ProvisionedPackage>> {
         use crate::provision::{PackageKind, provision_package};
         let (toolchain, framework) =
-            orchestrator::avr_packages(inputs.project_dir, Some(inputs.env_config), inputs.board)?;
+            orchestrator::avr_packages(inputs.project_dir, Some(inputs.env_config), inputs.board)
+                .await?;
         Ok(vec![
             provision_package(PackageKind::Toolchain, &toolchain, mode).await,
             provision_package(PackageKind::Framework, &framework, mode).await,