Fix KeyError in SocketInterface.shutdown() when worker exits during wait

[jan-janssen]

Summary

• SocketInterface.shutdown() unconditionally indexed the reply dict returned by send_and_receive_dict() with ["result"].
• receive_dict() can instead return {"error": ExecutorlibSocketError(...)} if the worker process exits while shutdown() is waiting for its reply (a benign race - the worker simply finished/exited on its own).
• That race raised a KeyError: 'result' inside SocketInterface.__del__, which Python cannot propagate from a destructor, so it prints a confusing Exception ignored in: <function SocketInterface.__del__> traceback during garbage collection (e.g. when Jupyter releases old cached objects) even though nothing actually crashed.
• Fix: only read the "result" key when it's present, otherwise shutdown() returns None for this benign race instead of raising.

Test plan

• Added test_interface_shutdown_with_process_exiting_during_wait, which uses a spawner whose poll() reports the process alive only once (matching the real race window) and asserts shutdown() no longer raises.
• Full test suite run pending (this environment's MPI/network setup makes the broader suite slow to run interactively).

Summary by CodeRabbit

• Bug Fixes
  • Improved shutdown handling when a worker exits while the interface is waiting for a response.
  • Shutdown now completes reliably when the worker’s response does not include a result.
  • Ensured shutdown returns the expected empty result and properly resets the connection state.
  • Prevented shutdown waits from leaving the communication interface in an inconsistent state.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: 6c26f541-ee3b-4327-a2cb-c47337d1cc6a

📥 Commits

Reviewing files that changed from the base of the PR and between a9037e9 and f839b1b.

📒 Files selected for processing (1)

• tests/unit/standalone/interactive/test_communication.py

Included review availability: Your plan provides up to 1 included review per hour; 0 remain after this review.

---

📝 Walkthrough

Walkthrough

SocketInterface.shutdown now tolerates shutdown responses without a "result" key. A regression test simulates a worker exiting while shutdown(wait=True) waits for a response and verifies that the method returns None.

Changes

Interactive shutdown

Layer / File(s)	Summary
Shutdown response handling and regression coverage src/executorlib/standalone/interactive/communication.py, tests/unit/standalone/interactive/test_communication.py	SocketInterface.shutdown retains None when the response has no "result" key. The test double simulates process exit during the wait, and the test verifies that shutdown(wait=True) returns None.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Merge Risk: ⚪ Minimal · up to f839b

Interactive shutdown now handles a worker exiting during response waiting without raising a destructor traceback.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 14.29% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 7 functions across 2 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: fixing the KeyError in SocketInterface.shutdown() when the worker exits during the wait.
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.

• Fix all pre-merge checks with AI

✨ Finishing Touches 💡 2

📝 Generate docstrings 💡

• Create stacked PR
• Commit on current branch

🛠️ Fix failing CI checks 💡

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/socket-interface-shutdown-race

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.26%. Comparing base (851b1a0) to head (f839b1b).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1063   +/-   ##
=======================================
  Coverage   94.25%   94.26%           
=======================================
  Files          39       39           
  Lines        2176     2178    +2     
=======================================
+ Hits         2051     2053    +2     
  Misses        125      125           

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.