ci: use a count-based fuzztime limit to dodge a Go toolchain race - #229
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Duration-based -fuzztime (e.g. 5s) hits a known unfixed race in internal/fuzz where the context deadline used to stop workers can leak past the code that's supposed to suppress it as a normal stop signal, failing the run with a bare "context deadline exceeded" and no crasher input (golang/go#75804). Confirmed against upstream repro output and the Go team's own workaround: reproduces regardless of fuzztime length (seen from 3s to 10+ minutes upstream), and the fix (CL 804900) only just landed in release-branch.go1.27, not yet in any released stable/oldstable toolchain. Switching to a count-based limit (Nx) avoids the wall-clock deadline context entirely, sidestepping the race rather than gambling that a longer duration makes it less likely. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
etiennep
approved these changes
Jul 30, 2026
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Summary
Run Fuzz TestsCI step (go test -fuzz=FuzzAppendSanitizedMetricName -fuzztime=5s -parallel=2 ./datadog) intermittently fails with a barecontext deadline exceededand no crasher input.internal/fuzzpackage (golang/go#75804): the context deadline used to stop workers at the end of-fuzztimecan leak past the code meant to suppress it as a normal stop signal.888a447,stableGo leg only, go1.26.5) — matches the upstream repro output byte-for-byte, and reproduces regardless of-fuzztimeduration per the Go team's own testing (seen from 3s to 10+ minutes). The fix (CL 804900) only merged intorelease-branch.go1.27on 2026-07-23 and isn't in any released stable/oldstable toolchain yet.-fuzztime=1000000x) instead of a wall-clock duration, which avoids thecontext.WithTimeoutdeadline path entirely and sidesteps the race rather than gambling on duration.Test plan
go test -fuzz=FuzzAppendSanitizedMetricName -fuzztime=1000000x -parallel=2 ./datadoglocally — stops precisely atexecs: 1000000, passes cleanly (~14s).🤖 Generated with Claude Code