FC-acceptance-probe-cannot-distinguish-revisions.json

{
  "schema_version": 1,
  "id": "FC-acceptance-probe-cannot-distinguish-revisions",
  "violated_contract": "A promotion smoke that reads a public URL must prove the candidate revision is serving, not only that some revision of the same service is healthy. A canary marker that is identical for every build (frontend:ready) lets the load balancer keep the previous revision live while the smoke still passes, so the post-promotion accept/rollback decision cannot distinguish the new candidate from the revision it was meant to replace. On 2026-09-01 the frontend promotion accepted frontend-700415b-33560919436-1 at h.omi.me on a marker the previous revision also rendered.",
  "canonical_prevention": "Bake the candidate's full commit SHA into the same hidden canary as a distinct data-omi-public-build-sha attribute, pass that SHA as --expect-sha through both smoke invocations, and retry the public-URL route until the SHA matches. Targets that do not declare {sha} keep the ready-marker-only probe.",
  "canonical_prevention_artifact": [
    ".github/scripts/smoke_public_build_browser.py",
    ".github/scripts/test_check_public_build_contract.py"
  ],
  "evidence_prs": [],
  "scope_hints": [
    ".github/actions/public-build-candidate-promotion/**",
    ".github/actions/deploy-public-build/**",
    ".github/scripts/smoke_public_build_browser.py",
    ".github/scripts/check_public_build_contract.py",
    "config/public-build-contract.json",
    "web/frontend/src/components/public-build-canary.tsx"
  ],
  "status": "open"
}