fix: make the init-repo test fixture collision-proof under parallel threads - #25
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TempFolder::new() named its directory git-it-init-test-{pid}-{nanos}. The
four initialize_repository tests run on parallel threads in one process, so
the pid is shared and two threads could read the same nanosecond; fs::create_dir
then failed with AlreadyExists and the unwrap() panicked. A different one of
the four failed on each run, which is what made it look random.
Replace the wall-clock stamp with a process-wide AtomicU32 counter, matching
the TempRepo fixtures in ops.rs and ops_worktree.rs. pid + counter cannot
collide by construction, so create_dir is kept over create_dir_all: a
collision should now be impossible, and would be a real bug worth panicking on.
Verified with five consecutive full cargo test runs, all green.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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The previous commit claimed pid + counter "cannot collide by construction" and kept `create_dir` over `create_dir_all` on that basis. That reasoning only holds among LIVE processes. The counter restarts at zero every run, so uniqueness rests entirely on the pid never repeating — and a pid is unique only while its process is alive. A run killed before `Drop` (Ctrl-C on cargo test, or a panic=abort) leaves its directories behind; once the OS recycles that pid, a fresh process counting from zero reproduces the exact same path and `create_dir(...).unwrap()` panics with AlreadyExists. Not hypothetical: this machine currently holds 36 orphaned `gte-*` fixture directories spanning 18 distinct pids. Remove any leftover first, then `create_dir_all` — the same two lines the TempRepo fixtures in ops.rs, ops_worktree.rs, ops_merge.rs, ops_rewrite.rs and graph.rs already use. Those fixtures were right and this one was the outlier; the extra line is the point, not redundancy. Reported by Codex review on #25. cargo test -p git-core: 183 passed. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This was referenced Aug 8, 2026
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What
cargo testintermittently failed one of the fourgit_ops::tests::initialize_repository_*tests. Pre-existing flake, unrelated to any feature work.Cause
TempFolder::new()built its path asgit-it-init-test-{pid}-{nanos}and then calledfs::create_dir(&path).unwrap(). All four tests run on parallel threads in one process, so the pid is shared and two threads can read the same nanosecond;create_dirthen fails withAlreadyExistsand theunwrap()panics. A different one of the four failed on each run, which is what made it look random.Fix
Replace the wall-clock stamp with a process-wide
AtomicU32counter — the pattern theTempRepofixtures inops.rsandops_worktree.rsalready use.pid + countercannot collide by construction.Kept
create_dirovercreate_dir_alldeliberately: a collision is now impossible, so if one ever happens it should panic loudly rather than be absorbed. The now-unusedSystemTime/UNIX_EPOCHimport is removed.Test plan
cargo test -p git-core initialize_repository -- --test-threads=1— 4/4 passcargo testruns, all green (the flake needed repetition to surface)git_may_fail,read_file) are pre-existing dead test helpers in other filesNote
Other
TempRepofixtures (ops_rewrite.rs,ops_remote.rs,graph.rs,ops_merge.rs) each define their own. Any that derive uniqueness from a timestamp rather than a counter could flake the same way under enough parallelism — not touched here since none are currently failing.🤖 Generated with Claude Code