fix: sandbox2: tolerate socket unlink failure in Listener::drop

[gominimal-aw-bot]

Routing-Key: inbox-route/I_kwDOSUhdos8AAAABMrkmdA

The Drop impl for Listener<C> in crates/sandbox2/src/listener.rs called std::fs::remove_file(&self.socket_path).unwrap(), so any unlink error — a racing cleanup that already removed the socket, or a permission error — panicked the destructor. Because Drop runs during stack unwind from an earlier panic on sandbox teardown after a failed build, that second panic escalates to abort(), terminating minimald and every concurrent session. No adversarial input is required: a failed build plus a stale socket is enough. The fix logs the error via tracing::warn! and continues, tolerating the stale-socket condition at shutdown. Prior hardening added catch_unwind in the channel handler loop but did not cover this destructor (informed by #152). A broader audit of other Drop impls for the same panic-on-cleanup pattern is left as follow-up.

Verification

cargo fmt --all --check --manifest-path target/Cargo.toml — passed, no drift
cargo clippy --workspace --locked -- -D warnings — passed, no warnings
cargo build --workspace --locked — passed
cargo test --workspace --locked — passed, exit 0 (all unit + doctests green)

Note

Fix Listener drop to warn instead of panic on socket file removal failure

In listener.rs, the Drop impl for Listener previously called unwrap() on std::fs::remove_file, causing a panic if the socket file could not be removed. It now logs a warning via tracing::warn and continues without panicking.

^{Macroscope summarized 31e6132.}

Summary by CodeRabbit

• Bug Fixes
  • Improved shutdown reliability by preventing cleanup failures from causing a panic.
  • Cleanup issues are now logged as warnings instead of interrupting the application.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 195d4bde-7386-4021-a8e0-a1f85a2709f4

📥 Commits

Reviewing files that changed from the base of the PR and between 1a1025e and 31e6132.

📒 Files selected for processing (1)

• crates/sandbox2/src/listener.rs

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📝 Walkthrough

Walkthrough

Listener::drop now logs a warning when socket-file removal fails. The cleanup path no longer panics on this error.

Changes

Socket cleanup

Layer / File(s)	Summary
Listener drop cleanup crates/sandbox2/src/listener.rs	Listener::drop logs a warning when remove_file fails instead of unwrapping the error and panicking.

Estimated code review effort: 1 (Trivial) | ~2 minutes

Merge Risk: ⚪ Minimal · up to 31e61

The change prevents socket cleanup failures from causing a shutdown panic while preserving normal cleanup behavior. No actionable merge-blocking risk remains after normal checks and review.

Suggested reviewers: 0chroma

Poem

I hop by the socket at close of day,
A failed cleanup no longer holds sway.
The warning is logged,
The panic is fogged,
And the listener bounds away.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title uses the required Conventional Commit format and clearly describes the socket unlink failure handling change.
Description check	✅ Passed	The description explains the failure mode, fix, impact, follow-up scope, and verification results, but it omits the template headings and checklist.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch inbox-patch/sandbox2-listener-drop-unwrap-3244e2d35b8d911a

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