Wait for pending derivations before checking validity - #61
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jacobmichels wants to merge 1 commit into
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jacobmichels
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joshheinrichs-shopify and
lilyinstarlight
September 6, 2026 03:17
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Why
macOS CI on
mainfails inflakes / provenanceafter the test clears its store and restores a package from a binary cache. The provenance check, which checks how the package was built, reports that it cannot recreate the package's.drvfile (its build recipe).A validity lookup can race with an asynchronous recipe write. The write clears the cached metadata, but an earlier lookup can finish afterward and cache a stale “missing” result. Waiting only before the final validity check is too late.
Change
Wait for any queued write in
AttrCursor::forceDerivation()before the first validity lookup. Keep the existing regeneration path for recipes that are genuinely absent.Add a deterministic regression test that completes a write between a missing-path lookup and the caching of its result. It uses a temporary local store and a controlled write schedule, without threads or sleeps. The test reproduces the same error before the fix and passes afterward.
Checks
nix develop -c meson compile -C buildnix develop -c meson test -C build --no-rebuild --print-errorlogs nix-expr-tests eval-cache provenancenix develop -c ./maintainers/format.shLocal checks run on Linux. macOS confirmation remains with CI.