[https://nvbugs/6450338][fix] Replace class-based isinstance check with the existing…

[trtllm-agent]

Summary

• Root cause: isinstance(self.mpi_session, MpiPoolSession) raises TypeError because tests/test_common/session_reuse.py rebinds proxy.MpiPoolSession to a factory function
• Fix: Replace class-based isinstance check with the existing self.mpi_session.is_comm_session() predicate; unwaive the previously-skipped test
• Automated fix generated by repair-bot

Test plan

• Verify fix on the same GPU type as the original failure
• Check for regressions in related tests

Links

• Bug: https://nvbugs/6450338

Summary by CodeRabbit

• Bug Fixes

  • Improved worker startup status handling across supported session types.
  • Prevented worker process monitoring from being skipped due to session classification issues.

• Tests

  • Removed an obsolete integration test waiver, allowing the affected accuracy test to run normally.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: d5fec9ba-c9e5-47af-ac29-a922e27c0c6e

📥 Commits

Reviewing files that changed from the base of the PR and between 46bf21b and 9e11f94.

📒 Files selected for processing (2)

• tensorrt_llm/executor/proxy.py
• tests/integration/test_lists/waives.txt

💤 Files with no reviewable changes (1)

• tests/integration/test_lists/waives.txt

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📝 Walkthrough

Walkthrough

The executor now identifies non-communication MPI sessions polymorphically when processing worker initialization status. The related GPT-OSS integration test waiver is removed.

Changes

MPI worker initialization

Layer / File(s)	Summary
Polymorphic worker status handling tensorrt_llm/executor/proxy.py, tests/integration/test_lists/waives.txt	Worker identities are extracted from three-item status payloads using is_comm_session(), and the matching integration test waiver is removed.

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

Possibly related PRs

• NVIDIA/TensorRT-LLM#16338: Updates the same worker identity registration flow used by local MPI worker monitoring.
• NVIDIA/TensorRT-LLM#16411: Makes a corresponding change to MPI session status interpretation.
• NVIDIA/TensorRT-LLM#16417: Changes the session predicate used for worker identity extraction.

Suggested reviewers: zhaoyangwang-nvidia

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title uses the required ticket/type format and matches the main fix in the change set.
Description check	✅ Passed	The description clearly explains the issue, fix, test plan, and bug link, though it omits the template's PR checklist section.
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 unit tests (beta)

• Create PR with unit tests

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[dongfengy]

Thanks for the automated attempt, but this doesn't address the failure tracked in https://nvbugs/6450338. That failure is a plain accuracy assertion (GPQA 55.051 vs threshold 55.734) — there is no TypeError anywhere in the CI logs — and tests/test_common/session_reuse.py cited in the root-cause analysis is not part of this repository, so the isinstance issue looks like an artifact of the repair sandbox rather than the CI failure. Since the underlying accuracy flakiness isn't addressed, un-waiving the test isn't safe yet. Closing this PR.