Reproduce · detect · prevent

Failures become useful when they become executable.

A clean-room field guide to autonomous coding-agent failures. Every entry includes a bounded fixture, deterministic detector, repair invariant, and regression proof.

4 patterns

FFA-001 · verification

Stale green CI evidence

hypothetical provenance

misleading-successstale-evidencecoverage-gap
FFA-002 · orchestration

Result-channel mismatch

hypothetical provenance

timeoutphantom-waitignored-result
FFA-003 · coordination

Concurrent queue update loss

hypothetical provenance

lost-updatesilent-data-lossclean-history
FFA-004 · testing

Timezone-dependent test

hypothetical provenance

environment-driftmidnight-failureflaky-test