fix: match SDK capture frames across demangler renderings

[cat-ph]

Problem

CI on main went red after #176 merged: from_error_builds_exception_list_with_stacktrace fails on Linux with expected user frame last, got "<posthog_rs::error_tracking::Exception>::from_error::<...>".

Root cause is not the wire-order flip itself: is_internal_capture_frame matches SDK capture helpers by substring (e.g. Exception::from_error), but newer toolchain/demangler output renders qualified paths as <posthog_rs::error_tracking::Exception>::from_error::<T> — the closing > breaks the substring match, so the SDK frame survives the strip and sits at the crash-site end of the canonical order. The PR's own CI was green a week earlier under the older rendering, and macOS still renders bracket-free, which is why this only surfaced on the post-merge Linux run. Exception::from_message and Client::capture_exception had the same latent hole.

Released 0.19.0 carries the bug: manual from_error/capture_exception captures built under newer toolchains keep one SDK frame at the stack tail (consistent per error, so grouping is stable — but the tail frame is wrong and the fingerprint includes SDK noise).

Changes

• is_internal_capture_frame strips </> from the demangled name before matching, so both renderings (and monomorphized generic suffixes) hit all existing patterns. Panic/unwind runtime frames remain deliberately unmatched, as before.
• Regression test pinning both renderings for the affected helpers, plus a non-SDK name that must not match.
• patch changeset → 0.19.1. The cymbal wire-order cutoff is 0.19.0, so the patch passes the gate as canonical, which is correct — it contains the flip.

How did you test this code?

Automated only:

• Reproduced the exact main failure in a Linux container (rust:1, current stable), then verified the fix: all 28 error_tracking tests pass there, including the previously failing one.
• Full cargo test --lib on macOS (188 passed) — the older bracket-free rendering still matches.
• Pre-existing personal_api_key deprecation warnings in test_on_error.rs (from feat: add secret_key config, deprecate personal_api_key #174) are untouched/out of scope.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Claude Code diagnosed and fixed this under my direction: pulled the failing main run, reproduced in a Linux container to get the assertion text CI logs omitted, bisected the discrepancy to demangler rendering differences rather than the #176 logic, and validated on both renderings.

[github-actions]

posthog-rs-v0 Compliance Report

Date: 2026-07-10 16:35:30 UTC
Duration: 15547ms

✅ All Tests Passed!

46/46 tests passed

---

Capture Tests

✅ 29/29 tests passed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	143ms
Format Validation.Event Has Uuid	✅	143ms
Format Validation.Event Has Lib Properties	✅	144ms
Format Validation.Distinct Id Is String	✅	144ms
Format Validation.Token Is Present	✅	143ms
Format Validation.Custom Properties Preserved	✅	144ms
Format Validation.Event Has Timestamp	✅	148ms
Retry Behavior.Retries On 503	✅	5153ms
Retry Behavior.Does Not Retry On 400	✅	2150ms
Retry Behavior.Does Not Retry On 401	✅	2143ms
Retry Behavior.Respects Retry After Header	✅	5099ms
Retry Behavior.Implements Backoff	✅	15101ms
Retry Behavior.Retries On 500	✅	5103ms
Retry Behavior.Retries On 502	✅	5099ms
Retry Behavior.Retries On 504	✅	5097ms
Retry Behavior.Max Retries Respected	✅	15100ms
Deduplication.Generates Unique Uuids	✅	100ms
Deduplication.Preserves Uuid On Retry	✅	5023ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	10031ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5034ms
Deduplication.No Duplicate Events In Batch	✅	27ms
Deduplication.Different Events Have Different Uuids	✅	23ms
Compression.Sends Gzip When Enabled	✅	23ms
Batch Format.Uses Proper Batch Structure	✅	25ms
Batch Format.Flush With No Events Sends Nothing	✅	37ms
Batch Format.Multiple Events Batched Together	✅	106ms
Error Handling.Does Not Retry On 403	✅	2089ms
Error Handling.Does Not Retry On 413	✅	2095ms
Error Handling.Retries On 408	✅	5091ms

Feature_Flags Tests

✅ 17/17 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	57ms
Request Payload.Flags Request Uses V2 Query Param	✅	61ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	22ms
Request Payload.Flags Request Omits Authorization Header	✅	27ms
Request Payload.Token In Flags Body Matches Init	✅	42ms
Request Payload.Groups Round Trip	✅	36ms
Request Payload.Groups Default To Empty Object	✅	36ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	45ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	45ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	36ms
Request Lifecycle.No Flags Request On Init Alone	✅	16ms
Request Lifecycle.No Flags Request On Normal Capture	✅	50ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	50ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	36ms
Retry Behavior.Retries Flags On 502	✅	245ms
Retry Behavior.Retries Flags On 504	✅	243ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	46ms

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[github-actions]

posthog-rs-v1 Compliance Report

Date: 2026-07-10 16:36:14 UTC
Duration: 22654ms

✅ All Tests Passed!

111/111 tests passed

---

Capture_V1 Tests

✅ 94/94 tests passed

View Details

Test	Status	Duration
Endpoint And Method.Targets V1 Endpoint	✅	94ms
Endpoint And Method.Does Not Use Legacy Endpoints	✅	95ms
Required Headers.Has Authorization Bearer Header	✅	95ms
Required Headers.Has Content Type Json	✅	94ms
Required Headers.Has Posthog Sdk Info Format	✅	96ms
Required Headers.Has Posthog Attempt Header	✅	93ms
Required Headers.Has Posthog Request Id	✅	93ms
Required Headers.Has Posthog Request Timestamp	✅	97ms
Required Headers.Has User Agent	✅	95ms
Body Format.Body Has Created At And Batch	✅	92ms
Body Format.No Api Key In Body	✅	76ms
Body Format.No Sent At In Body	✅	89ms
Event Format.Event Has Required Root Fields	✅	87ms
Event Format.Event Uuid Is Valid	✅	90ms
Event Format.Event Timestamp Is Rfc3339	✅	89ms
Event Format.Distinct Id Is String	✅	88ms
Event Format.Distinct Id At Root Not Properties	✅	88ms
Event Format.Custom Properties Preserved	✅	90ms
Event Format.Set Properties Preserved	✅	87ms
Event Format.Set Once Properties Preserved	✅	84ms
Event Format.Groups Properties Preserved	✅	83ms
Event Format.Sdk Generates Uuid If Not Provided	✅	75ms
Event Format.Event Has Required Root Fields Batch	✅	101ms
Event Format.Event Uuid Is Valid Batch	✅	101ms
Event Format.Event Timestamp Is Rfc3339 Batch	✅	101ms
Event Format.Distinct Id Is String Batch	✅	100ms
Event Format.Distinct Id At Root Not Properties Batch	✅	100ms
Event Format.Custom Properties Preserved Batch	✅	99ms
Event Format.Set Properties Preserved Batch	✅	99ms
Event Format.Set Once Properties Preserved Batch	✅	98ms
Event Format.Groups Properties Preserved Batch	✅	89ms
Event Format.Sdk Generates Uuid If Not Provided Batch	✅	85ms
Batch Behavior.Multiple Events In Single Batch	✅	115ms
Batch Behavior.Batch Envelope Smoke	✅	95ms
Batch Behavior.Flush With No Events Sends Nothing	✅	58ms
Batch Behavior.Flush At Triggers Batch	✅	1080ms
Batch Behavior.Created At Reflects Batch Creation Time	✅	63ms
Deduplication.Generates Unique Uuids	✅	105ms
Deduplication.Different Events Same Content Different Uuids	✅	68ms
Deduplication.Preserves Uuid On Retry	✅	5068ms
Deduplication.Preserves Timestamp On Retry	✅	5041ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5069ms
Deduplication.No Duplicate Events In Batch	✅	85ms
Header Behavior On Retry.Attempt Header Starts At One	✅	49ms
Header Behavior On Retry.Attempt Header Increments On Retry	✅	10049ms
Header Behavior On Retry.Request Id Preserved On Retry	✅	5032ms
Header Behavior On Retry.Different Requests Have Different Request Ids	✅	2041ms
Header Behavior On Retry.Request Timestamp Changes On Retry	✅	5030ms
Response Format Validation.Success Response Has Uuid Keyed Results	✅	29ms
Response Format Validation.Success Response Has Ok For Each Event	✅	20ms
Response Format Validation.Success No Retry After When All Ok	✅	20ms
Response Format Validation.Success Retry After Present When Retry Events	✅	21ms
Response Format Validation.Success No Retry After When Drop Only	✅	22ms
Response Format Validation.Response Echoes Request Id	✅	19ms
Retry Behavior.Retries On 408	✅	5022ms
Retry Behavior.Retries On 500	✅	5016ms
Retry Behavior.Retries On 503	✅	5016ms
Retry Behavior.Retries On 504	✅	5015ms
Retry Behavior.Retryable Errors Have Retry After	✅	2016ms
Retry Behavior.Respects Retry After On Retryable Error	✅	8015ms
Retry Behavior.Does Not Retry On 400	✅	2023ms
Retry Behavior.Does Not Retry On 401	✅	2021ms
Retry Behavior.Does Not Retry On 402	✅	2017ms
Retry Behavior.Does Not Retry On 413	✅	2016ms
Retry Behavior.Does Not Retry On 415	✅	2015ms
Retry Behavior.Non Retryable Errors Have No Retry After	✅	2017ms
Retry Behavior.Implements Backoff	✅	15023ms
Retry Behavior.Max Retries Respected	✅	15021ms
Partial Batch Handling.Handles 200 Full Success	✅	2034ms
Partial Batch Handling.Handles 200 With All Ok	✅	3029ms
Partial Batch Handling.Does Not Retry Dropped Events	✅	3029ms
Partial Batch Handling.Does Not Retry Limited Events	✅	3015ms
Partial Batch Handling.Prunes Ok Events On Partial Retry	✅	5015ms
Partial Batch Handling.Prunes Dropped Events On Partial Retry	✅	5018ms
Partial Batch Handling.Retries Only Retry Events From Partial	✅	5017ms
Partial Batch Handling.Partial Retry Preserves Uuids	✅	5017ms
Partial Batch Handling.Partial Retry Attempt Header Increments	✅	5022ms
Partial Batch Handling.Partial Retry Request Id Preserved	✅	5022ms
Partial Batch Handling.Respects Retry After On Partial	✅	5015ms
Partial Batch Handling.Unknown Result Treated As Terminal	✅	3017ms
Partial Batch Handling.Mixed Ok Drop Limited No Retry	✅	3019ms
Compression.Sends Gzip Content Encoding	✅	14ms
Compression.No Content Encoding When Disabled	✅	13ms
Compression.Compressed Body Is Decompressible	✅	13ms
Error Handling.Does Not Retry On Unknown 4Xx	✅	2013ms
Event Options.Cookieless Mode Override	✅	15ms
Event Options.Disable Skew Correction Override	✅	14ms
Event Options.Process Person Profile Override	✅	14ms
Event Options.Product Tour Id Override	✅	13ms
Event Options.Unset Options Omitted	✅	13ms
Event Options.Options Override In Batch	✅	14ms
Geoip And Historical Migration.Geoip Disable Injected Into Properties	✅	13ms
Geoip And Historical Migration.Historical Migration Set In Body	✅	13ms
Geoip And Historical Migration.Historical Migration Absent By Default	✅	13ms

Feature_Flags Tests

✅ 17/17 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	9ms
Request Payload.Flags Request Uses V2 Query Param	✅	10ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	10ms
Request Payload.Flags Request Omits Authorization Header	✅	10ms
Request Payload.Token In Flags Body Matches Init	✅	9ms
Request Payload.Groups Round Trip	✅	9ms
Request Payload.Groups Default To Empty Object	✅	9ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	9ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	9ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	10ms
Request Lifecycle.No Flags Request On Init Alone	✅	6ms
Request Lifecycle.No Flags Request On Normal Capture	✅	13ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	11ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	9ms
Retry Behavior.Retries Flags On 502	✅	213ms
Retry Behavior.Retries Flags On 504	✅	214ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	15ms