[sean0407]

Summary

A persistent venv can retain a dangling package-directory symlink after the Python runtime changes. When initialization then creates a runtime file link beneath that path, os.makedirs(..., exist_ok=True) raises FileExistsError instead of recovering.

Remove the parent symlink only when it is confirmed dangling, then create the directory and the current runtime file link. Fixes #4269.

Checks

• Before: the issue reproduction raised FileExistsError at the parent-directory creation in a credential-isolated sandbox.
• After: cached_venv_replaces_dangling_package_symlink_test passed in the same isolated sandbox (1 test); it checks that the stale package link becomes a directory and the child link resolves to the current runfiles file.
• git diff --check passed.

The focused run was on macOS. Windows execution, Bazel, and buildifier were not run.

AI assistance: OpenAI Codex assisted with the patch and regression test; Sean is the submitting author.

[aignas]

I see the CI is failing in quite a few places, could you please check it?

[sean0407]

Thanks for flagging this. I checked Buildkite build #18004 and found a Buildifier formatting failure in the new BUILD target (tests/bootstrap_impls/BUILD.bazel); I reordered the attributes and pushed commit 3d94855 to fix that. The Ubuntu/RBE Bazel jobs in #18004 also failed, but their visible log output only reports that the Bazel build did not complete, without identifying the failing target. The new commit is now pushed, and I am checking its CI result before calling the remaining failures resolved.

[sean0407]

Correction to my update above: build #18005 still flagged the same Buildifier check, so my first attribute reorder was incomplete. I moved main after data to match the existing BUILD target ordering and pushed e6da0b7. Buildkite #18006 and the Read the Docs build for this commit are now running; I will report their results when available.

[sean0407]

Update: build #18006 no longer reports the Buildifier formatting annotation (the only current annotation is a Debian 11 end-of-life warning). The overall Buildkite check still fails: the visible failed jobs are Ubuntu/Bazel 9 and Debian/Bazel 8 and 9; their logs end with a generic Bazel build failure and do not identify a failing target. Read the Docs is still running. I have not treated the remaining jobs as passing.

[sean0407]

Thanks for asking me to check the CI. Buildkite #18006 exposed a Pyrefly error in the new regression test: Rlocation(...) has type str | None, so passing it directly to pathlib.Path is rejected. I added an explicit non-None assertion in b88ba42. Python syntax and the patch policy pass; the patch remains 3 files / 101 lines with no binary changes. Buildkite #18007, metadata checks, and Read the Docs are now queued or pending; I will share the result when they finish.

[sean0407]

Update: Buildkite #18007 passed in 11m 33s, Read the Docs succeeded, and both GitHub Actions checks passed. All four reported checks are green on b88ba42. The PR remains open and still awaits maintainer review.