fix(noema-review): close item13 stale-head native-cancellation race

[seonghobae]

Summary

docs/doctoring/item13-stale-head-cancellation-audit-20260903.md (a 9-agent audit, adversarially re-verified) found a real, unfixed bug: noema-review.yml's concurrency: group has no head-SHA component, and native cancel-in-progress is conditional on synchronize/closed. GitHub evaluates a workflow's concurrency group at run-creation time, before any job or step runs, using only the triggering event's payload. If GitHub ever delivers an older push's synchronize event after a newer push's event (delivery order is not guaranteed), the older run's mere entry into the shared group cancels the newer, valid, current-head run immediately — before that older run's own "Reject a stale trigger before credential or model setup" step ever gets a chance to self-abort. strix.yml and opencode-review.yml were already documented as avoiding this exact hazard; noema-review.yml was the one central workflow still using the unguarded pattern.

Root cause verification against current main

Confirmed unchanged before implementing: noema-review.yml's workflow-level concurrency: block is still group: noema-review-- (PR-number only) with cancel-in-progress: ${{ github.event_name == 'pull_request_target' && (action == 'synchronize' || action == 'closed') }} — exactly as the audit describes.

However, strix.yml's and opencode-review.yml's own concurrency shape has moved on since the audit doc's verdict paragraph was written (both dated the same day, 2026-09-03), so this PR does not copy the head-SHA-scoping pattern the audit doc points to as "the fix":

• opencode-review.yml's own in-file comment documents that its head-SHA-scoped group (the #1568 fix the audit doc cites) was tried and reverted the same day — scoping by head SHA gave every push its own group, so rapid successive pushes stopped cancelling each other's in-flight runs and instead queued up independently, worsening this org's measured self-inflicted queue-thrashing pattern (236/300 cancelled runs from concurrent push volume).
• Both strix.yml and opencode-review.yml now use job-level concurrency (not workflow-level), scoped to the long-running job only by repository+PR-number (no SHA), with cancel-in-progress unconditionally false — so the active run in that group is never natively preempted, at any event arrival order. A structurally separate cleanup job with no concurrency block of its own (so it's never blocked by that group) performs the actual, live-head-validated retirement via a direct Actions API call (strix.yml's cancel-superseded-pr-runs, opencode-review.yml's cancel-superseded-opencode-review-runs).

This fix mirrors that current, real, dual-precedent pattern rather than the now-superseded head-SHA-scoping one.

Fix (round 1)

• Removes noema-review.yml's workflow-level concurrency: block.
• noema-review job gets its own job-level concurrency: group (same PR-number-scoped formula, unchanged), cancel-in-progress unconditionally false — no event arrival order can let native cancellation kill a genuinely current run.
• Extracts the existing "Cancel superseded Noema runs after live-head validation" logic — previously a step nested inside the very job it needed to unblock — into a new, structurally separate cancel-superseded-noema-runs job with no concurrency block of its own, mirroring strix.yml/opencode-review.yml.
• Moves actions: write from the noema-review job to the new cleanup job (the only job that still calls the cancel API).
• Records the fix in docs/product-technical-gap-baseline.md's item 13 entry (documentation only, not merge authorization).

Fix (round 2 — Devin Review + owner PR review corrections)

Devin Review found that round 1 was itself incomplete: cancel-in-progress: false only protects the group's RUNNING slot. GitHub silently replaces the group's single PENDING slot the instant another trigger enters it, regardless of cancel-in-progress — a current-head run sitting pending behind a still-running older-head run can be evicted by a third, out-of-order/stale trigger before it ever gets a runner, erased before its own stale-trigger guard ever executes.

• Added queue: max to the noema-review job's concurrency block (group formula and cancel-in-progress: false unchanged). This is this repo's own established fix for exactly this failure mode — first added to current-head-run-coalescer.yml after an identical two-round Devin Review finding there, and already standard for agent-mention-router.yml, agent-mention-opencode-dispatch.yml, and agent-mention-noema-dispatch.yml (docs/doctoring/agent-mention-concurrency-isolation.md). Safe/cheap here specifically because "Reject a stale trigger before credential or model setup" runs immediately, before any credential minting, sidecar provisioning, or LLM call — unlike strix.yml, whose own live-head validation sits much later and which therefore deliberately does not use queue: max, relying instead on pr-review-merge-scheduler.yml to re-dispatch exact-head evidence at merge time. Residual, documented risk: queue: max's retention cap is 100 pending runs (GitHub-imposed) and GitHub does not guarantee strict FIFO order for retained runs — the same caveat already recorded for current-head-run-coalescer.yml.
• Corrected an inaccurate claim from round 1: round 1 said cancel-superseded-noema-runs was "Extended to also cover repository_dispatch retries." The owner's PR review caught that this used the plain github.token against the target repository's Actions API — for pull_request_target, the required-workflow ruleset materializes the run inside the target repository itself so github.token is correctly scoped there, but a repository_dispatch retry is posted to the target repository's own dispatches endpoint independently of where this run executes, so the same token is not guaranteed scoped to whatever repository the dispatch payload names. Reverted that job's scope to pull_request_target only, matching what its token can actually authenticate for. A correctly token-scoped repository_dispatch cleanup path is tracked separately in ContextualWisdomLab/.github#1799, not attempted here.

Test plan

• tests/test_noema_review_gate.py — test_noema_concurrency_and_live_head_cleanup_preserve_current_review rewritten for the job-level group / cancel-in-progress: false / queue: max / relocated, pull_request_target-only cleanup job. New test_noema_review_job_retains_pending_current_head_run_under_stale_trigger_burst is the executable regression contract for the pending-preservation fix (structural pin on queue: max + the early-exit ordering of the stale-trigger guard, matching this repo's own convention for this GHA-runtime-behavior class of test in tests/test_current_head_coalescer_self_cancellation.py).
• tests/test_required_workflow_queue_contract.py — test_required_pull_request_workflows_cancel_superseded_runs's and test_noema_triggers_preserve_standalone_pull_request_review's noema-review.yml branches updated to assert queue: max.
• tests/test_noema_orchestrator_workflow_contract.py / tests/test_required_review_runner_image_contract.py — unaffected by round 2 (job count/boundaries unchanged).

Developer experience

• python3 -c "import yaml; yaml.safe_load(open('.github/workflows/noema-review.yml'))" — parses; job order cancel-closed-pr-runs, cancel-superseded-noema-runs, noema-review; only noema-review carries a concurrency: block (now with queue: max); no workflow-level concurrency: remains.
• Every run: block (14 total, round 2 removed one dead step) independently extracted via PyYAML and checked with bash -n — all pass.
• Full suite (Python 3.12, matching this repo's CI target): coverage run -m pytest tests -q → 2722 passed, 1 skipped, 21 subtests passed.
• coverage report --show-missing → 100% statement+branch on scripts/ci/ (fail_under = 100).
• interrogate → RESULT: PASSED (minimum: 100.0%, actual: 100.0%).
• scripts/ci/test_strix_quick_gate.sh → test_strix_quick_gate: PASS (unaffected non-regression check; strix.yml itself is untouched).

User experience

No behavior change for a PR whose pushes arrive in order (the common case). For the rare pending-eviction case round 2 targets: a stale trigger arriving while the current head's review is queued behind an older-head run can no longer silently erase that queued review — it now survives to get its own runner instead. repository_dispatch cross-repo cleanup is no longer claimed by this PR (see round 2 above); #1799 carries that.

Related

• docs/doctoring/item13-stale-head-cancellation-audit-20260903.md — the audit this PR closes the one confirmed, deferred finding from.
• docs/doctoring/noema-review-failure-retrospective-and-improvement-plan-20260903.md — recommends a broader shared assert_head_is_live() primitive across 5 hand-rolled guards; out of scope here, not attempted.
• docs/doctoring/agent-mention-concurrency-isolation.md — the established queue: max precedent round 2 applies here.
• ContextualWisdomLab/.github#1661 — a separate, much larger, still-open/blocked PR whose diff independently arrived at nearly this same noema-review.yml restructuring.
• ContextualWisdomLab/.github#1788 — the precedent for a concurrency-format contract-test sync fix of this shape.
• ContextualWisdomLab/.github#1799 — the canonical successor for token-scoped repository_dispatch cleanup support, split out per round 2 above.

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Review configuration:

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Team

Run ID: 73ec502a-f397-49db-a9b1-2949f099dfcb

📥 Commits

Reviewing files that changed from the base of the PR and between 0b99db6 and 1abd324.

📒 Files selected for processing (2)

• .github/workflows/noema-review.yml
• tests/test_required_workflow_queue_contract.py

📝 Walkthrough

Walkthrough

noema-review의 워크플로 수준 동시성을 제거했습니다. PR 번호 기반의 비취소 작업 동시성을 추가했습니다. 라이브 PR 헤드를 검증한 뒤 이전 Noema 실행을 취소하는 별도 작업을 추가하고 관련 계약 테스트와 문서를 갱신했습니다.

Changes

Noema 동시성 제어

Layer / File(s)	Summary
워크플로 동시성 및 취소 흐름 .github/workflows/noema-review.yml, docs/product-technical-gap-baseline.md	워크플로 수준 concurrency를 제거했습니다. noema-review에는 cancel-in-progress: false인 작업 수준 동시성을 추가했습니다. cancel-superseded-noema-runs는 라이브 PR 헤드를 확인한 뒤 이전 활성 실행을 Actions API로 취소합니다.
동시성 계약 검증 tests/test_noema_review_gate.py, tests/test_required_workflow_queue_contract.py, tests/test_required_review_runner_image_contract.py	새 작업 수준 동시성, 작업 순서, 권한 분리, 실행 이미지 수를 검증하도록 테스트를 변경했습니다. repository_dispatch에서도 취소 작업이 실행되도록 조건 검증을 갱신했습니다.
워크플로 추출 기준 갱신 tests/test_noema_orchestrator_workflow_contract.py	계약 테스트가 새 cancel-superseded-noema-runs 단계와 작업을 기준으로 스크립트를 추출하도록 변경했습니다.

Estimated code review effort: 4 (Complex) | ~45 minutes

Merge Risk: 🟠 High · up to 0b99d

A delayed event for an older PR head can still displace the pending Noema review for the current head, leaving the latest change unreviewed. This race should be fixed before merge.

Suggested reviewers: claude

Sequence Diagram(s)

sequenceDiagram
  participant PREvent as PR 이벤트
  participant CancelJob as cancel-superseded-noema-runs
  participant ActionsAPI as Actions API
  participant NoemaReview as noema-review
  PREvent->>CancelJob: PR 번호와 현재 헤드 전달
  CancelJob->>ActionsAPI: 활성 Noema 실행 조회
  CancelJob->>CancelJob: 라이브 PR 헤드 재검증
  CancelJob->>ActionsAPI: 이전 헤드 실행 취소
  PREvent->>NoemaReview: PR 번호 기반 리뷰 작업 실행

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✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 7 functions across 4 files. (2 skipped: 2 …
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.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	제목은 noema-review.yml의 stale-head 네이티브 취소 경쟁 상태를 수정하는 PR의 주요 변경 사항을 정확하고 구체적으로 요약합니다.

Full details: Docstring Coverage

Explanation

Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 7 functions across 4 files. (2 skipped: 2 unsupported.)

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[seonghobae]

현재 merge blocker와 successor 경계

이 PR은 #1661의 대형 혼합 delta를 그대로 병합하는 대신 item 13의 Noema native cancellation race를 좁게 수리하는 올바른 successor입니다. 현재 head 0b99db6c1f6c38b8db8ad5e53be5b939ce19fdd6은 mergeable이지만 아직 병합할 수 없습니다.

확인된 blocker:

1. noema-review에 queue: max가 없어, current-head job이 pending인 동안 delayed stale trigger가 들어오면 single pending slot에서 current job이 밀릴 수 있습니다.
2. repository_dispatch cleanup이 GH_TOKEN: ${{ github.token }}으로 sibling TARGET_REPOSITORY의 Actions API를 호출합니다. 중앙 .github token에는 그 권한이 없으므로 실질 지원이 아닙니다. canonical successor는 #1799입니다.
3. exact-head hosted checks 9개가 모두 queued이고, 독립 승인도 없습니다.

권장 최소 delta:

• 이 PR: job-level queue: max, cancel-in-progress: false, group=noema-review-{repository}-{PR번호}, cleanup job은 group 밖, native current/stale pending 순서 회귀 테스트.
• repository_dispatch: target-scoped token을 이 PR에서 안전하게 완성하지 않는다면 cleanup 지원 범위에서 제거하고 #1799로 넘김.
• docs(orchestrator): confirm orchestrator/free pin, audit gateway enforcement #1661: fix(noema-review): close item13 stale-head native-cancellation race #1797·#1799와 별도 successor가 모든 유효 delta를 검증해 승계할 때까지 유지하되, 이 PR에 무관한 telemetry·scheduler·hash-lock delta를 다시 섞지 않음.

다른 로컬 세션은 이 head를 수정한 뒤 RED와 GREEN, 정확한 head SHA, unresolved thread 0, hosted check 결과를 이 PR에 남겨 주십시오.

기다리는 동안 다른 로컬 세션에게 지속적으로 지시 받아 도우세요. 계속 묻고 계속 피드백하고 계속 지원하세요. 더 주도적이고 더 적극적으로요.

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Actionable comments posted: 1

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Inline comments:
In @.github/workflows/noema-review.yml:
- Line 373: Adjust the workflow so cancel-superseded-noema-runs exposes whether
the run is the live head, and make noema-review depend on that job while
entering the concurrency group only for live-head triggers; add a regression
test covering this ordering and update documentation and contract-test wording
to match the native cancellation behavior.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Team

Run ID: d1b8dde0-6ca3-42d4-a188-77b772d02aee

📥 Commits

Reviewing files that changed from the base of the PR and between 232107a and 0b99db6.

📒 Files selected for processing (6)

• .github/workflows/noema-review.yml
• docs/product-technical-gap-baseline.md
• tests/test_noema_orchestrator_workflow_contract.py
• tests/test_noema_review_gate.py
• tests/test_required_review_runner_image_contract.py
• tests/test_required_workflow_queue_contract.py

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[seonghobae]

Devin Review finding — confirmed and fixed

Root cause confirmed. cancel-in-progress: false on noema-review's job-level concurrency group only protects the group's currently RUNNING slot. GitHub Actions concurrency groups still keep exactly one PENDING slot and silently replace it the instant another trigger enters the group — this happens unconditionally, independent of cancel-in-progress. Sequence: an older head H1 running, a current head H2 queued behind it, then a third out-of-order or duplicate-stale trigger H3 arrives — GitHub evicts H2 from the pending slot before H2's own "Reject a stale trigger before credential or model setup" step ever executes. H2 is erased, not rejected; H3 typically self-aborts once it gets a runner (proving the guard works when a run does get to execute), but nothing is left queued to review the actual current head. This is documented GitHub Actions platform behavior, not something specific to this workflow.

Investigated before choosing a fix, per this repo's own precedent (not guessed): searched for an existing "don't lose a pending job" pattern and found this org already solved this exact failure mode twice — current-head-run-coalescer.yml hit an identical two-round Devin Review finding (round 1: cancel-in-progress: false alone, caught as incomplete; round 2: queue: max actually closed it), and agent-mention-router.yml / agent-mention-opencode-dispatch.yml / agent-mention-noema-dispatch.yml already use queue: max as standing convention (docs/doctoring/agent-mention-concurrency-isolation.md). By contrast, strix.yml deliberately does not use queue: max — its own live-head validation runs much later in its job (after real setup work), so it relies on pr-review-merge-scheduler.yml re-dispatching exact-head evidence at merge time instead. noema-review's own stale-trigger guard runs immediately (before any credential minting, sidecar provisioning, or LLM call), which is exactly why queue: max is the safe, cheap, precedented choice here rather than strix's alternative.

Fix applied: added queue: max to the noema-review job's existing concurrency block (group: formula and cancel-in-progress: false unchanged, matching the owner's requested noema-review-{repository}-{PR number} scoping). This retains up to 100 pending runs per group instead of silently replacing the previous one, so a current-head run survives to get its own runner once the running one finishes rather than being evicted. Cleanup job stays outside this concurrency group, unchanged in that respect. Documented residual risk, not eliminated: queue: max's retention cap is 100 pending runs (GitHub-imposed, cannot be raised) and GitHub does not guarantee strict FIFO order for retained runs — the same caveat already on record for current-head-run-coalescer.yml. No incident at that scale has been observed for this workflow.

Separately addressed the owner's blocker #2: this PR's round-1 extension of cancel-superseded-noema-runs to also accept repository_dispatch used the plain github.token against the target repository's Actions API. For pull_request_target, the required-workflow ruleset materializes the run inside the target repository itself so github.token is correctly scoped there — but a repository_dispatch retry is posted to the target repository's own dispatches endpoint independently of where this run executes, so the same token is not guaranteed scoped to whatever repository the payload names. Reverted that job's if: to pull_request_target only, matching what its token can actually authenticate for, and stripped the corresponding claims from the job's comments, env fallbacks, and the PR description. repository_dispatch cleanup support is deferred to #1799 as the canonical successor, not attempted here.

Executable regression test

Added test_noema_review_job_retains_pending_current_head_run_under_stale_trigger_burst (tests/test_noema_review_gate.py): pins queue: max present / cancel-in-progress: true absent in the noema-review job's own concurrency block, the unchanged repository+PR-number group formula (still no head-SHA segment), and the step ordering that keeps the stale-trigger guard ahead of credential minting, sidecar provisioning, and the model call — the closest executable proxy available, since the actual eviction is GitHub scheduler behavior outside this repo's code, matching this repo's own convention for this test class (tests/test_current_head_coalescer_self_cancellation.py). Updated the existing concurrency-contract assertions in tests/test_noema_review_gate.py and tests/test_required_workflow_queue_contract.py to match both changes.

Verification evidence (RED → GREEN)

• Before this commit: queue: max absent from noema-review's concurrency block; the new regression test and the updated contract assertions fail against that shape (RED).
• After this commit: coverage run -m pytest tests -q → 2722 passed, 1 skipped, 21 subtests passed (up from 2721 — one new test).
• coverage report --show-missing → 100% statement+branch on scripts/ci/ (fail_under = 100).
• interrogate → RESULT: PASSED (minimum: 100.0%, actual: 100.0%).
• scripts/ci/test_strix_quick_gate.sh → PASS (unaffected non-regression check; strix.yml itself untouched).
• python3 -c "import yaml; yaml.safe_load(open('.github/workflows/noema-review.yml'))" parses; all 14 run: blocks independently pass bash -n.

Status

• Exact head SHA: e52f849be1e7c0a2b2aa7c9345319cf7f1164581 (pushed non-force to fix/noema-review-stale-head-cancellation-race; base still main@232107a0).
• Unresolved review threads: 0 — Devin's finding thread resolved above.
• Hosted checks on this head: currently queued org-wide (consistent with this org's documented near-zero Actions-admission capacity constraint, docs/doctoring/actions-plan-concurrency-ceiling-20260903.md) — no hosted-check results to report yet as of this comment; all local verification above (tests/coverage/docstrings/bash syntax) is real, executed evidence, not a substitute for those checks completing.
• PR description updated to correct the round-1 repository_dispatch claim and record round 2 in full.

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