{"abstract":"The activity completion operation is admitted even though a timed-out activity attempt overwrites its successor.","category":"Workflow orchestration","checks":9,"contract":"Return a Boolean admission decision for accept a durable activity completion. The record r must satisfy all of: r['run_identity'][0] == r['run_identity'][1]; r['activity_attempt'][0] == r['activity_attempt'][1]; r['activity_scheduled'][0] in r['activity_scheduled'][1]; set(r['result_schema'][0]) <= set(r['result_schema'][1]); r['completion_pending'] == 'pending'. Extra tracing fields are ignored; validation does not mutate the record.","evaluation_group":"xd-activity-completion","failed_approach":"Adding the activity attempt check repairs the reported defect, but replacing the adjacent activity scheduled check loses that independent invariant.","family":"xd-activity-completion-activity_attempt","id":"FA-1131","implementations":{"attempt":{"sha256":"483cf1bff214e0e7927c046522946770908d01819bad9db3df75c7ea04db7baa","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(r):\n    return (r['run_identity'][0] == r['run_identity'][1]) and (r['activity_attempt'][0] == r['activity_attempt'][1]) and (set(r['result_schema'][0]) <= set(r['result_schema'][1])) and (r['completion_pending'] == 'pending')\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nr = {'run_identity': ['r2', 'r2'], 'activity_attempt': [3, 3], 'activity_scheduled': ['a', ['a', 'b']], 'result_schema': [['receipt'], ['receipt']], 'completion_pending': 'pending'}\ncheck('valid operation', solve(r), True)\ncheck('A completion from a previous workflow run is accepted', solve(dict(r, **{'run_identity': ['r1', 'r2']})), False)\ncheck('A timed-out activity attempt overwrites its successor', solve(dict(r, **{'activity_attempt': [2, 3]})), False)\ncheck('An unsolicited completion invents an unscheduled activity', solve(dict(r, **{'activity_scheduled': ['c', ['a', 'b']]})), False)\ncheck('An incompatible activity result enters durable history', solve(dict(r, **{'result_schema': [['receipt'], ['error']]})), False)\ncheck('A duplicate activity completion schedules downstream work twice', solve(dict(r, **{'completion_pending': 'completed'})), False)\ncheck('unrelated tracing metadata', solve(dict(r, trace='run-'+str(N))), True)\ncheck('repeat validation is pure', solve(r), True)\ninvalid = {'run_identity': ['r1', 'r2'], 'activity_attempt': [2, 3], 'activity_scheduled': ['c', ['a', 'b']], 'result_schema': [['receipt'], ['error']], 'completion_pending': 'completed'}\nkeys = list(invalid)\npair = {keys[N % len(keys)]: invalid[keys[N % len(keys)]], keys[(N+1) % len(keys)]: invalid[keys[(N+1) % len(keys)]]}\ncheck('two independent violations in variant', solve(dict(r, **pair)), False)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"a776de2c2f97f0270903aae2327702f151c269da121e0cbe8d0c16ccd2629283","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(r):\n    return (r['run_identity'][0] == r['run_identity'][1]) and (r['activity_scheduled'][0] in r['activity_scheduled'][1]) and (set(r['result_schema'][0]) <= set(r['result_schema'][1])) and (r['completion_pending'] == 'pending')\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nr = {'run_identity': ['r2', 'r2'], 'activity_attempt': [3, 3], 'activity_scheduled': ['a', ['a', 'b']], 'result_schema': [['receipt'], ['receipt']], 'completion_pending': 'pending'}\ncheck('valid operation', solve(r), True)\ncheck('A completion from a previous workflow run is accepted', solve(dict(r, **{'run_identity': ['r1', 'r2']})), False)\ncheck('A timed-out activity attempt overwrites its successor', solve(dict(r, **{'activity_attempt': [2, 3]})), False)\ncheck('An unsolicited completion invents an unscheduled activity', solve(dict(r, **{'activity_scheduled': ['c', ['a', 'b']]})), False)\ncheck('An incompatible activity result enters durable history', solve(dict(r, **{'result_schema': [['receipt'], ['error']]})), False)\ncheck('A duplicate activity completion schedules downstream work twice', solve(dict(r, **{'completion_pending': 'completed'})), False)\ncheck('unrelated tracing metadata', solve(dict(r, trace='run-'+str(N))), True)\ncheck('repeat validation is pure', solve(r), True)\ninvalid = {'run_identity': ['r1', 'r2'], 'activity_attempt': [2, 3], 'activity_scheduled': ['c', ['a', 'b']], 'result_schema': [['receipt'], ['error']], 'completion_pending': 'completed'}\nkeys = list(invalid)\npair = {keys[N % len(keys)]: invalid[keys[N % len(keys)]], keys[(N+1) % len(keys)]: invalid[keys[(N+1) % len(keys)]]}\ncheck('two independent violations in variant', solve(dict(r, **pair)), False)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"fixed":{"sha256":"c39ba7de8344a2e46d65b9212399f6a99908626f6f026316dea695596c517697","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(r):\n    return (r['run_identity'][0] == r['run_identity'][1]) and (r['activity_attempt'][0] == r['activity_attempt'][1]) and (r['activity_scheduled'][0] in r['activity_scheduled'][1]) and (set(r['result_schema'][0]) <= set(r['result_schema'][1])) and (r['completion_pending'] == 'pending')\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nr = {'run_identity': ['r2', 'r2'], 'activity_attempt': [3, 3], 'activity_scheduled': ['a', ['a', 'b']], 'result_schema': [['receipt'], ['receipt']], 'completion_pending': 'pending'}\ncheck('valid operation', solve(r), True)\ncheck('A completion from a previous workflow run is accepted', solve(dict(r, **{'run_identity': ['r1', 'r2']})), False)\ncheck('A timed-out activity attempt overwrites its successor', solve(dict(r, **{'activity_attempt': [2, 3]})), False)\ncheck('An unsolicited completion invents an unscheduled activity', solve(dict(r, **{'activity_scheduled': ['c', ['a', 'b']]})), False)\ncheck('An incompatible activity result enters durable history', solve(dict(r, **{'result_schema': [['receipt'], ['error']]})), False)\ncheck('A duplicate activity completion schedules downstream work twice', solve(dict(r, **{'completion_pending': 'completed'})), False)\ncheck('unrelated tracing metadata', solve(dict(r, trace='run-'+str(N))), True)\ncheck('repeat validation is pure', solve(r), True)\ninvalid = {'run_identity': ['r1', 'r2'], 'activity_attempt': [2, 3], 'activity_scheduled': ['c', ['a', 'b']], 'result_schema': [['receipt'], ['error']], 'completion_pending': 'completed'}\nkeys = list(invalid)\npair = {keys[N % len(keys)]: invalid[keys[N % len(keys)]], keys[(N+1) % len(keys)]: invalid[keys[(N+1) % len(keys)]]}\ncheck('two independent violations in variant', solve(dict(r, **pair)), False)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":" This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"xd-activity-completion-activity_attempt","generated_at":"2026-09-29T14:36:59.194833+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic local contract for workflow orchestration. Each negative fixture violates exactly one invariant. No transport timing, persistence, cryptographic verification, or full protocol implementation is claimed.","repair":"Require r['activity_attempt'][0] == r['activity_attempt'][1] together with every other stated precondition before accepting the operation.","root_cause":"The admission path omits the activity attempt invariant while validating the other operation preconditions.","sha256":"3d9e94ae5e8cc29f48b4572f82684308e49e03b7e2ca9854b47c6617a4e7bb34","title":"Accept a durable activity completion: A timed-out activity attempt overwrites its successor · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":30.65,"exit_code":1,"observations":[{"actual":true,"check":"valid operation","expected":true,"passed":true},{"actual":false,"check":"A completion from a previous workflow run is accepted","expected":false,"passed":true},{"actual":false,"check":"A timed-out activity attempt overwrites its successor","expected":false,"passed":true},{"actual":true,"check":"An unsolicited completion invents an unscheduled activity","expected":false,"passed":false},{"actual":false,"check":"An incompatible activity result enters durable history","expected":false,"passed":true},{"actual":false,"check":"A duplicate activity completion schedules downstream work twice","expected":false,"passed":true},{"actual":true,"check":"unrelated tracing metadata","expected":true,"passed":true},{"actual":true,"check":"repeat validation is pure","expected":true,"passed":true},{"actual":false,"check":"two independent violations in variant","expected":false,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"valid operation\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"A completion from a previous workflow run is accepted\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A timed-out activity attempt overwrites its successor\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"An unsolicited completion invents an unscheduled activity\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"An incompatible activity result enters durable history\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A duplicate activity completion schedules downstream work twice\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"unrelated tracing metadata\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"repeat validation is pure\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"two independent violations in variant\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":36.29,"exit_code":1,"observations":[{"actual":true,"check":"valid operation","expected":true,"passed":true},{"actual":false,"check":"A completion from a previous workflow run is accepted","expected":false,"passed":true},{"actual":true,"check":"A timed-out activity attempt overwrites its successor","expected":false,"passed":false},{"actual":false,"check":"An unsolicited completion invents an unscheduled activity","expected":false,"passed":true},{"actual":false,"check":"An incompatible activity result enters durable history","expected":false,"passed":true},{"actual":false,"check":"A duplicate activity completion schedules downstream work twice","expected":false,"passed":true},{"actual":true,"check":"unrelated tracing metadata","expected":true,"passed":true},{"actual":true,"check":"repeat validation is pure","expected":true,"passed":true},{"actual":false,"check":"two independent violations in variant","expected":false,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"valid operation\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"A completion from a previous workflow run is accepted\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A timed-out activity attempt overwrites its successor\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"An unsolicited completion invents an unscheduled activity\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"An incompatible activity result enters durable history\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A duplicate activity completion schedules downstream work twice\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"unrelated tracing metadata\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"repeat validation is pure\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"two independent violations in variant\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":32.949,"exit_code":0,"observations":[{"actual":true,"check":"valid operation","expected":true,"passed":true},{"actual":false,"check":"A completion from a previous workflow run is accepted","expected":false,"passed":true},{"actual":false,"check":"A timed-out activity attempt overwrites its successor","expected":false,"passed":true},{"actual":false,"check":"An unsolicited completion invents an unscheduled activity","expected":false,"passed":true},{"actual":false,"check":"An incompatible activity result enters durable history","expected":false,"passed":true},{"actual":false,"check":"A duplicate activity completion schedules downstream work twice","expected":false,"passed":true},{"actual":true,"check":"unrelated tracing metadata","expected":true,"passed":true},{"actual":true,"check":"repeat validation is pure","expected":true,"passed":true},{"actual":false,"check":"two independent violations in variant","expected":false,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"valid operation\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"A completion from a previous workflow run is accepted\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A timed-out activity attempt overwrites its successor\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"An unsolicited completion invents an unscheduled activity\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"An incompatible activity result enters durable history\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A duplicate activity completion schedules downstream work twice\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"unrelated tracing metadata\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"repeat validation is pure\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"two independent violations in variant\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}