Lesson 268: Unity CI Concurrency Cancel Library Poison Receipt on BUILD_RECEIPT (2026)

Direct answer: Before November 2026 fest Addressables promotion, promote ci_cancel_safe_receipt_v1.json with X1–X6 gates—split concurrency groups so lint may cancel but Addressables may not mid-catalog, add rm -rf Library cleanup with if: always() after cancel weeks, document X4 cancel repro, and fail-close addressables_build_exclusive_ok on BUILD_RECEIPT. Pair Concurrency cancel preflight (Guide #30), 3-day no false green challenge scenario F, and cousin Lesson 261 (unity_ci_library_cache_receipt_v1 cache key—not cancel boundaries).

Why this matters now (November CI cancel edges)

November 2026 teams add concurrency: cancel-in-progress on main to stop double CI—then a fast lint job and a slow Addressables player build share one group. Cancel fires during AddressablesPlayerBuildProcessor; the next job restores a half-written Library/ and passes compile until fest players hit InvalidKeyException. Lesson 267 wires async playtest CSV honesty; 268 wires CI cancel boundaries before Wednesday smoke.

Library cache preflight owns ContentState hash in the cache key; 268 owns cancel policy and post-cancel cleanup on BUILD_RECEIPT.

Beginner path (split groups → cleanup → receipt)

Time: ~55 minutes first November cancel week; ~15 minutes when workflow template exists.

Developer path (gates X1–X6)

Align with Guide #30 preflight—guide = ninety-second gate; 268 = BUILD_RECEIPT milestone.

Cousin receipt crosswalk

Do not merge schemas—reference paths in cousin_receipts only.

X1 — Split workflow concurrency groups

# .github/workflows/unity-fast.yml
concurrency:
  group: unity-fast-${{ github.ref }}
  cancel-in-progress: true

# .github/workflows/unity-addressables-player.yml
concurrency:
  group: unity-addressables-exclusive-${{ github.ref }}
  cancel-in-progress: false

Rule: Never share one concurrency.group between fast jobs and Addressables player jobs.

X2 — Disable cancel on Addressables-exclusive job

Single workflow file alternative:

jobs:
  addressables-build:
    concurrency:
      group: unity-addressables-exclusive-${{ github.ref }}
      cancel-in-progress: false

Document job name in receipt—Thursday row review column addressables_build_exclusive_ok.

X3 — Post-cancel Library cleanup

  cleanup-after-addressables:
    needs: addressables-build
    if: always()
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: rm -rf Library Temp

Run even when addressables-build is cancelled—partial StreamingAssets/aa must not cache forward.

X4 — Cancel repro matrix

1. Push commit A; start Addressables build.
2. Push commit B while A runs (trigger cancel if misconfigured).
3. Let job C start; verify Library/ was cleaned (X3).
4. Player smoke on artifact from C—catalog loads without InvalidKeyException.

Log cancel count and job ids in receipt cancel_repro_log. Pair 3-day challenge scenario F.

X5 — Fail-closed promotion jq (CI tail)

jq -e '.addressables_build_exclusive_ok == true' release-evidence/unity/ci-cancel/CI_CANCEL_SAFE_RECEIPT.json

Block merge to fest branch when receipt missing after any cancel week—pair Wednesday smoke.

ci_cancel_safe_receipt_v1.json

{
  "schema": "ci_cancel_safe_receipt_v1",
  "build_label": "november-closeout-2026-rc2",
  "workflow_paths": {
    "fast": ".github/workflows/unity-fast.yml",
    "addressables_exclusive": ".github/workflows/unity-addressables-player.yml"
  },
  "concurrency_groups": {
    "fast": "unity-fast-${{ github.ref }}",
    "addressables_exclusive": "unity-addressables-exclusive-${{ github.ref }}"
  },
  "addressables_job": "addressables-build",
  "cancel_in_progress_on_addressables": false,
  "post_cancel_cleanup_job": "cleanup-after-addressables",
  "cancel_repro_log": {
    "forced_cancel_count": 2,
    "recovery_job_id": "987654321",
    "player_smoke_invalid_key": false
  },
  "cousin_receipts": {
    "library_cache": "release-evidence/unity/ci-cache/UNITY_CI_LIBRARY_CACHE_RECEIPT.json",
    "playtest_csv_ingest": "release-evidence/playtest/playtest_csv_ingest_receipt_v1.json"
  },
  "gates": {
    "X1_split_groups": "pass",
    "X2_no_cancel_on_addressables": "pass",
    "X3_post_cancel_cleanup": "pass",
    "X4_cancel_repro": "pass",
    "X5_fail_closed": "pass",
    "X6_receipt": "pass"
  },
  "addressables_build_exclusive_ok": true,
  "ci_cancel_safe_ok": true,
  "content_update_promotion_allowed": true
}

Pin under release-evidence/unity/ci-cancel/CI_CANCEL_SAFE_RECEIPT.json.

BUILD_RECEIPT columns (November lane)

Key takeaways

1. Split concurrency groups—lint may cancel; Addressables may not mid-catalog.
2. rm -rf Library after cancel with if: always()—non-negotiable on fest months.
3. Fail-closed addressables_build_exclusive_ok before branch promotion.
4. Run Library cache preflight before cancel policy on strip weeks.
5. 3-day challenge scenario F validates cancel + clean ladder.
6. Invalid Key help triages runtime; 268 prevents false-green promotion.
7. 15-free GitHub Actions CI recipes bookmark build graphs—cancel policy is separate column.
8. Cousin Lesson 261 owns cache key material—not cancel boundaries.

Common mistakes

• One concurrency: group: unity-main for lint + Addressables (X1 fail).
• cancel-in-progress: true on Addressables job during catalog writes (X2 fail).
• Skipping cleanup when job status is cancelled (X3 fail).
• Blaming cache key when cancel poisoned Library/ (Lesson 261 cousin).
• Promoting after cancel week without X4 repro on clean runner.
• Merging ci_cancel_safe_receipt with unity_ci_library_cache_receipt schemas.

Troubleshooting

Mini exercise (50 minutes)

1. Audit workflow YAML—log X1 group names.
2. Misconfigure shared group once—confirm X4 repro catches poison.
3. Add X3 cleanup job with if: always().
4. Wire X5 jq gate in workflow tail.
5. File receipt; BUILD_RECEIPT GREEN for ci_cancel_safe_ok.
6. Crosswalk cousin Lesson 261 path in cousin_receipts.

Continuity — November 2026 fest close-out + playtest triage (266–276)

Previous: Lesson 267 — Discord playtest thread CSV ingest receipt
Next: Lesson 269 — Godot export VDF LF line ending steamcmd receipt

FAQ

Same as Lesson 261?
261 = actions/cache key + ContentState hash; 268 = concurrency split + post-cancel Library/ cleanup.

Same as 3-day challenge scenario F?
Challenge owns F1–F6 ladder calendar; 268 owns ci_cancel_safe_receipt_v1 BUILD_RECEIPT column.

Same as Guide #30?
Guide = ninety-second preflight; 268 = course milestone with promotion jq + cancel repro log.

Help #30 when it ships?
Fix lane when cancel already corrupted Library/; 268 prevents promotion without X1–X6.

Resource #28 when it ships?
Bookmark list for safe concurrency patterns—see 12 patterns listicle until Resource row publishes.

Can we delete actions/cache instead?
No—run Lesson 261 cache key lane and 268 cancel lane.

Does this replace Wednesday smoke?
No—binary smoke is separate; 268 stops false-green CI before smoke runs.

November CI lies when cancel-in-progress interrupts Addressables—split groups, clean Library/ after cancel, fail-closed addressables_build_exclusive_ok, then promote.