If in doubt, delete the uv.lock file

判断

Library maintainers and CI owners on Python 3.15 must choose whether to delete a stray uv.lock to clear a PyO3 build failure, accepting that the next run may resolve different dependency versions.

依据

Simon Willison writes that since switching to Python 3.15 he gets occasional confusing Python dependency errors, and his rule is: “If in doubt, delete the uv.lock file.” Most of his projects are libraries that do not include a uv.lock, because locking versions for downstream users would be rude. Running uv run pytest can leave uv.lock files that are listed in .gitignore and not committed. Sometimes that lock pins a dependency without a Python 3.15 wheel; his example is error: Failed to build watchfiles==1.1.1, with maturin.build_wheel failing because the configured Python interpreter version (3.15) is newer than PyO3’s maximum supported version (3.14). Deleting the file and running uv run pytest again usually fixes it. Mechanism: the stale lock can hold an incompatible pin, so clearing it lets uv re-resolve and attempt a build under 3.15.