[mypyc] Fix free-threading race condition in argument parsing#21613
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Global argument parser state initialization was missing synchronization. Don't use a mutex on the hot path as an optimization. Fixes #21578.
ilevkivskyi
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Jun 15, 2026
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Nice! Hopefully this should fix the parallel parsing race.
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Global argument parser state initialization was missing synchronization.
Don't use a mutex on the hot path as an optimization.
Fixes #21578 (probably). I added a regression test that failed about 30% of time on master (on macOS).
I used coding agent assist.