Re:Rewind VM: a flaky build you only catch once
by 77rushi77 on Monday October 05, 2026 @12:00AM
(#49960531)
The SIGPIPE case that never failed in 20,000 laptop runs but failed on the first Rewind run is a strong result. One thing I wonder about is "same result under all 65 schedules" only rules out failures that happen more than roughly 5% of the time. Is there a way to see how many schedules rarer races need, say 1 in 1,000?
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Re:Rewind VM: a flaky build you only catch once
by setheron on Monday October 05, 2026 @12:14AM
(#49960608)
You can ask for as many schedules as you need `rewind check --all --schedules 3000` (for 1 in 1_000 lets say) but the code also pushes the scheduler toward bad timing: it switches threads at random points and sometimes stalls a process for up to about a millisecond, the way a busy CI machine would.