{"task_id":"st_01a00b4b","status":"completed","residency_state":"evicted","parent_session_id":"01a00387-aaf8-7f2f-89e3-e24c1af24859","root_session_id":"01a00387-aaf8-7f2f-89e3-e24c1af24859","depth":1,"execution_mode":"in-process","model":"openai-codex/gpt-5.6-sol","notify_on_terminal":true,"created_at":"2026-08-16T15:58:32.208Z","updated_at":"2026-08-18T23:49:03.420Z","notification":{"run_epoch":0,"notified_epoch":0},"name":"gate20-overlay-debug","task_summary":"Diagnose adaptive overlay Gate20 failure","description":"Diagnose adaptive overlay Gate20 failure","category":"deep","requested_model":{"provider":"openai-codex","model_id":"gpt-5.6-sol","display":"openai-codex/gpt-5.6-sol","source":"category","variant":"medium","reasoning_effort":"medium"},"fallback_models":[{"provider":"clinepass","model_id":"cline-pass/deepseek-v4-pro","display":"clinepass/cline-pass/deepseek-v4-pro","source":"category","variant":"medium","reasoning_effort":"medium"},{"provider":"clinepass","model_id":"cline-pass/glm-5.2","display":"clinepass/cline-pass/glm-5.2","source":"category","variant":"medium","reasoning_effort":"medium"}],"resolved_model":{"provider":"openai-codex","model_id":"gpt-5.6-sol","display":"GPT-5.6 Sol","source":"category","variant":"medium","reasoning_effort":"medium"},"spawn_spec":{"version":1,"cwd":"/home/cube/projects/richard/traning coach","prompt":"Read-only independent debugging of Gate20 failure for successor 4a8627af8f9b931d537e17dbd3e357b7a0f2b2abffdbf28f6ad19a8d32893ec0. Evidence root: /home/cube/projects/richard/traning coach/.omo/evidence/task26/task26-certification-deployment-4a8627af8f9b931d537e17dbd3e357b7a0f2b2abffdbf28f6ad19a8d32893ec0-v3-st_01a00b39. Failed adaptive node: test_overlay_recovery_rejects_symlink_and_data_inode_replacement. Form at least three hypotheses across candidate delta, test order/global leakage, and harness/filesystem semantics. Read the exact failure/JUnit, locate test and production seam, reproduce alone and in relevant order against exact successor and predecessor without editing. Distinguish candidate causality by toggling only the three successor delta files or using sealed snapshots. Return exact commands, outputs, root cause, and smallest test-first repair or corrected-harness action. Do not mutate files/services/network/Git/evidence/live state.\n\n<Category_Context name=\"deep\">\nYou are operating in DEEP mode. This is the category reserved for goal-oriented autonomous work on hairy problems that reward thorough exploration and comprehensive solutions.\n\nThe orchestrator chose this category because the task benefits from depth over speed. You should feel empowered to spend the time needed: five to fifteen minutes of silent exploration before the first edit is normal and correct. Rushing to implementation on a deep task is a failure mode, not a feature.\n\n# How deep mode adjusts the base behavior\n\n**Exploration budget: generous.** Read the files you need, trace dependencies both directions, fire 2-5 explore/librarian sub-agents in parallel for broader questions. Build a complete mental model before the first `apply_patch`. Exploration here is an investment, not overhead.\n\n**Goal, not plan.** You receive a GOAL describing the desired outcome. You figure out HOW to achieve it. The orchestrator deliberately did not hand you a step-by-step plan; producing one and asking for approval is not what was asked. Execute.\n\n**Atomic task treatment.** When the goal contains numbered steps or phases, treat them as sub-steps of ONE task and execute them all in this turn. Splitting them across turns is wrong unless they reveal an architectural blocker that requires the user's input. If the \"steps\" turn out to be genuinely independent tasks that should have been separate delegations, flag that in your final message and refuse the ones beyond scope.\n\n**Root cause bias.** Prefer root-cause fixes over symptom fixes. A null check around `foo()` is a symptom fix; fixing whatever causes `foo()` to return unexpected values is the root fix. Trace at least two levels up before settling on an answer. In deep mode, you have permission (and the expectation) to do the deeper fix.\n\n**Ambition scaled to context.** For brand-new greenfield work, be ambitious. Choose strong defaults, avoid AI-slop aesthetics, produce something you would be proud to hand to another senior engineer. For changes in an existing codebase, be surgical and respect the existing patterns; depth does not mean invasiveness.\n\n**Completion bar: full delivery.** \"Simplified version\", \"proof of concept\", and \"you can extend this later\" are not acceptable deliveries for a deep task. The orchestrator routed here specifically for a complete solution. If you hit a genuine blocker (missing secret, design decision only the user can make, three materially different attempts all failed), document it and return; otherwise, finish the task.\n\n**Status cadence: sparse.** The user is not on the other side of this conversation; the orchestrator is, and they will synthesize your progress. Send commentary only at meaningful phase transitions (starting exploration, starting implementation, starting verification, hitting a genuine blocker). Do not narrate every tool call; silence during focused work is expected.\n</Category_Context>"},"host_pid":1761519,"final_response":"I read this as a read-only Gate20 root-cause investigation - I inspected the evidence, reproduced both sealed variants, and isolated the harness-dependent test defect.\n\n## Verdict\n\nThis is **not candidate-caused**. The failure is a pre-existing test defect exposed by the certification harness’s `umask 077`.\n\nThe test injects:\n\n```python\nos.replace(replacement, path)\n```\n\nProduction correctly detects the inode replacement and raises:\n\n```text\nValueError: overlay journal file was replaced\n```\n\nBut the test then incorrectly expects `path` still to name the original inode. POSIX `os.replace` guarantees that `path` names the replacement inode. The original inode remains unchanged but unlinked.\n\n## Evidence chain\n\nThe primary Gate20 JUnit did not contain this failure. It contained three collection errors because the Hermes interpreter lacked `typer`.\n\nThe first corrected run executed zero tests because:\n\n```text\nERROR: Unknown config option: asyncio_default_fixture_loop_scope\n```\n\nThe authoritative failure is:\n\n```text\n...-gate20-corrected-v2-st_01a00b39/artifacts/corrected-source-package.junit.xml\n```\n\nIt reports 679 tests, 3 failures, including:\n\n```text\ntests.test_adaptive_nutrition\ntest_overlay_recovery_rejects_symlink_and_data_inode_replacement\n\nassert b'replacement' == complete + b'{\"torn\":'\n```\n\nThe production seam is `OverlayJournal._recover_locked`, particularly lines 7273-7282 of `adaptive_nutrition.py`, which compares the post-read named inode against the inode returned by `_read_overlay_rows_locked`.\n\n## Hypotheses tested\n\n1. **Candidate delta changed overlay behavior — refuted.**\n   - The only successor files are:\n     - `checkin_cli/customer_admin.py`\n     - `checkin_cli/activation_token_rotation_policy.py`\n     - `tests/test_customer_admin.py`\n   - `adaptive_nutrition.py` matches the sealed snapshot at SHA-256 `d3020f...342bcb`.\n   - Rebinding all three files to predecessor state gives the identical failure.\n\n2. **Test order/global leakage — order refuted, inherited global state confirmed.**\n   - The test fails alone and after its two preceding overlay tests under `umask 077`.\n   - It passes alone and in order under `umask 0022`.\n   - This is not leakage from another test. Both certification scripts explicitly execute `umask 077`.\n\n3. **Harness/filesystem semantics — confirmed root cause.**\n   - Under `0022`, `Path.write_bytes()` creates mode `0644`; production rejects the unsafe fixture before the monkeypatched `os.replace` executes, producing a false pass.\n   - Under `0077`, files are mode `0600`, so the replacement executes. Production detects it, but the test’s final pathname assertion is invalid.\n\n## Exact controlled results\n\nSuccessor alone, isolated bwrap, inherited `0022`:\n\n```text\n1 passed in 0.09s\nEXIT=0\n```\n\nSuccessor after preceding overlay tests, `0022`:\n\n```text\n3 passed in 0.10s\nEXIT=0\n```\n\nPredecessor three-file rebind, alone and ordered, `0022`:\n\n```text\n1 passed in 0.09s\n3 passed in 0.09s\n```\n\nThe same four commands prefixed with `umask 077`:\n\n```text\nsuccessor alone:       1 failed in 0.12s, EXIT=1\nsuccessor ordered:     1 failed, 2 passed in 0.12s, EXIT=1\npredecessor alone:     1 failed in 0.13s, EXIT=1\npredecessor ordered:   1 failed, 2 passed in 0.12s, EXIT=1\n```\n\nRepresentative command:\n\n```bash\numask 077\nbwrap --die-with-parent --unshare-net --ro-bind / / \\\n  --tmpfs /tmp --dev /dev --proc /proc \\\n  --setenv HOME /tmp --setenv TMPDIR /tmp \\\n  --setenv PYTHONDONTWRITEBYTECODE 1 \\\n  --setenv PYTHONPATH \"$S\" --chdir \"$S\" \\\n  /home/cube/miniconda3/bin/python -B -m pytest -q \\\n  -p no:cacheprovider \\\n  tests/test_adaptive_nutrition.py::test_overlay_recovery_rejects_symlink_and_data_inode_replacement\n```\n\nThe predecessor command additionally read-only bound the two predecessor files and `/dev/null` over the added module.\n\nProduction-level inode trace under `umask 077`:\n\n```text\nrecover_exception ValueError overlay journal file was replaced\nheld_mode 0o600\nheld_identity (84, 8)\nnamed_identity (84, 9)\nnamed_bytes b'replacement'\noriginal_inode_bytes_unchanged True\nEXIT=0\n```\n\n## Smallest test-first repair\n\nFix the test, not production or the harness:\n\n1. Explicitly `chmod(0o600)` both manually created files so the security path is exercised regardless of launcher umask.\n2. After recovery rejects the replacement, assert:\n   - the named path contains `b\"replacement\"`;\n   - optionally, through a descriptor opened before replacement, the original inode still contains `complete + b'{\"torn\":'`.\n\nConceptually:\n\n```python\npath.write_bytes(complete + b'{\"torn\":')\npath.chmod(0o600)\nreplacement.write_bytes(b\"replacement\")\nreplacement.chmod(0o600)\n\noriginal_fd = os.open(path, os.O_RDONLY)\ntry:\n    with pytest.raises(ValueError, match=\"unsafe|replaced\"):\n        journal.recover()\n\n    assert path.read_bytes() == b\"replacement\"\n    os.lseek(original_fd, 0, os.SEEK_SET)\n    assert os.read(original_fd, len(complete) + 8) == complete + b'{\"torn\":'\nfinally:\n    os.close(original_fd)\n```\n\nDo not “correct” the harness by changing its umask: that would restore a false-positive pass without testing inode replacement.\n\nNo repository, candidate, evidence, Git, service, or live-state files were changed.","run_stats":{"runtime_ms":327444,"turns":13,"tool_calls":43,"output_tokens":13263,"total_tokens":1524886,"generation_ms":275717,"tokens_per_second":48,"cost_usd":1.9126130000000001,"cache_hit_rate_last":0.9896025605170753,"cache_hit_rate_run":0.8884331609137993}}