multi-agent-mux/.agents/reports/reviewer-agy-01/report-e375099a.md

Code Review Report (2nd Round): fix/test-herdr-leak

• Job ID: e375099a
• Reviewer: agy (Session: herdr:reviewer-agy-01, Role: Reviewer)
• Date: 2026-10-13
• Target Branch: fix/test-herdr-leak
• Base Commit: 325b056057fcdd717d2c81017fc5ef57183cb4d0 (1st round review head)
• Head Commit: db7f4cab9c60ff5db009cf3fc625e9a86a465ef6 (Fix commit)
• Verification Path: /var/folders/q_/68sxgw3j073dgjg8wl9s08vw0000gn/T/mam-review/loop-20261013T010208Z-f90dd4/1
• Verification Environment: macOS (Darwin 24.3.0, arm64), Python 3.9.6, bash 3.2.57(1)-release, herdr 0.9.3

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1. Executive Summary

This 2nd-round review evaluated commit db7f4cab9c60ff5db009cf3fc625e9a86a465ef6, addressing non-blocking feedback from 1st-round reviews (claude 63919c5d and grok 191f0ec3):

• Finding: While HERDR_SOCKET_PATH, HERDR_PANE_ID, and HERDR_TAB_ID were stripped in mam_sandbox, HERDR_SESSION was still inherited from the ambient host environment.
• Impact: Although HERDR_SESSION on its own resolves under $HOME/.config/herdr/sessions/<session> (so sandboxing $HOME prevented socket file leaks), ambient-server helpers like _herdr_caller_server and pane_lock.caller_server() read HERDR_SESSION first. Consequently, tests branched on whether they were executed from within an agent pane or outside a pane.
• The Fix:
  1. tests/conftest.py:mam_sandbox: added monkeypatch.delenv("HERDR_SESSION", raising=False).
  2. tests/test_herdr_real_server_leak.py: added "HERDR_SESSION": "real" to PANE_VARS, covered by test_l2_sandbox_drops_the_pane_routing.

Verdict: PASS.

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2. Technical Evaluation

2.1 Environmental Isolation & Branching Consistency

• In lib_py/pane_lock.py:caller_server():

  def caller_server(env: Mapping[str, str]) -> str:
      if env.get("HERDR_SESSION"):
          return env["HERDR_SESSION"]
  

  And in lib.sh: HERDR_SESSION indicates that the current process runs inside an active herdr pane. By stripping HERDR_SESSION in mam_sandbox, every test begins with a clean non-pane baseline environment. Test behavior is now strictly reproducible regardless of whether the test runner runs inside an interactive terminal, CI, or an autonomous agent herdr session.

2.2 Test Compatibility

• Tests that explicitly test HERDR_SESSION configuration (e.g. test_issue50_dispatch_herdr.py:769, test_issue45_restore.py, test_tier1_unit.py) set the environment variable directly within the test body or pass it via env=... in subprocess calls. Because test bodies execute after fixture setup, their explicit settings take precedence and function properly.
• All 6 unit tests in tests/test_issue50_pane_lock.py (test_p1 to test_p5) and contract tests in tests/test_herdr_shim_contract.py pass cleanly.

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3. Test Verification Results

All tests executed with sanitized environment variables (env -u HERDR_SOCKET_PATH -u HERDR_PANE_ID -u HERDR_TAB_ID -u HERDR_WORKSPACE_ID -u HERDR_SESSION_NAME -u HERDR_SESSION -u WORKSPACE_ROOT -u MAM_ENV_FILE):

Test Suite / Target	Result	Execution Time
tests/test_herdr_real_server_leak.py	3 Passed	1.44s
tests/test_herdr_shim_contract.py:test_h26	2 Passed	3.98s
tests/test_issue50_pane_lock.py:test_p*	6 Passed	4.57s

• test_l2_sandbox_drops_the_pane_routing: Verifies that HERDR_SESSION is stripped by mam_sandbox alongside HERDR_SOCKET_PATH, HERDR_PANE_ID, HERDR_TAB_ID, HERDR_WORKSPACE_ID, and HERDR_SESSION_NAME.

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[VERDICT: PASS]