Discovered during Wave 4 prod validation 2026-05-11. Express 4-arg error middleware fires errorTracker.captureException then logger.error(err.stack) — but err.stack is a STRING so PostHogErrorTransport can't read the posthogCaptured dedup flag. Each uncaught error produces 2 $exception events instead of 1. Fix: pass err via { error: err } meta so Winston transport can read the flag.
Discovered during Wave 4 prod validation 2026-05-11. Express 4-arg error middleware fires
errorTracker.captureExceptionthenlogger.error(err.stack)— but err.stack is a STRING so PostHogErrorTransport can't read theposthogCaptureddedup flag. Each uncaught error produces 2 $exception events instead of 1. Fix: pass err via{ error: err }meta so Winston transport can read the flag.