ci: limit fuzz test to 2 parallel workers to avoid CI flakiness - #226
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go test -fuzz spawns one worker per CPU; on a contended runner a worker can miss the toolchain's hardcoded 1s response deadline, failing the whole run with "context deadline exceeded" unrelated to the code under test. Capping -parallel=2 reduces contention.
frajuqeb
approved these changes
Jul 29, 2026
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Summary
go test -fuzzspawns one worker subprocess per CPU. The Go toolchain enforces a hardcoded 1s response deadline per worker RPC; on a contended runner a worker can miss it, failing the whole run withcontext deadline exceededunrelated to the sanitizer code being tested (seen in https://github.com/segmentio/stats/actions/runs/30407686004/job/90436700862).-parallel=2on the fuzz step to reduce CPU contention between workers and avoid tripping that deadline.Test plan
fix-fuzz-ci-timeoutand confirmed CI is green (bothstableandoldstablematrix jobs, including the Run Fuzz Tests step): https://github.com/segmentio/stats/actions/runs/30433954592🤖 Generated with Claude Code