## Thinking Path
> - The `codex-local` adapter sets up a per-company Codex home with an
auth symlink. Between `lstat` and `symlink` there is a race where two
concurrent setups can both try to create the same symlink, surfacing
`EEXIST`.
> - Master already handles this at runtime via `createExpectedSymlink`,
which accepts `EEXIST` only when the raced-in entry resolves to the
expected source, and ships a regression test for the tolerated-race path
(symlink already points at the right place).
> - The symmetric path — `EEXIST` raised by a symlink pointing somewhere
else — must stay strictly rejected so a future refactor cannot silently
weaken the guard.
> - This PR locks that in with a single additive test. No production
code change.
## What Changed
- Added one regression test in
`packages/adapters/codex-local/src/server/codex-home.test.ts` that
injects an `EEXIST` whose raced-in symlink target points at a different
file, and asserts:
- `prepareManagedCodexHome` rejects with `code: "EEXIST"`.
- The mismatched symlink is left on disk (we do not blindly overwrite
the raced-in entry).
Complements the existing "treats a concurrently-created expected auth
symlink as success" test already on master.
Refs #5240 (Stack B — codex-home adapter session/auth handling).
## Verification
- `pnpm --filter @paperclipai/adapter-codex-local exec vitest run
src/server/codex-home.test.ts` — passes.
- `pnpm --filter @paperclipai/adapter-codex-local typecheck` — clean.
## Risks
- Test-only change. No production code is modified.
## Model Used
- Provider: Anthropic
- Model: Claude (Opus 4.7)
- Mode/capabilities: tool-using coding agent with shell execution and
test verification
## Checklist
- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] If this change affects the UI, I have included before/after
screenshots
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge
- [x] I searched the GitHub PR list for similar PRs and confirmed this
is not a duplicate
Co-authored-by: Devin Foley <devin@paperclip.ing>
Co-authored-by: Paperclip <noreply@paperclip.ing>
Abhishek gahlot
c32193c85e