{"abstract":"The workflow signal operation is admitted even though duplicate signal delivery applies the external command twice.","category":"Workflow orchestration","checks":9,"contract":"Return a Boolean admission decision for deliver a signal to a durable workflow. The record r must satisfy all of: r['signal_identity'][0] not in r['signal_identity'][1]; r['recipient_run'][0] == r['recipient_run'][1]; r['signal_declared'][0] in r['signal_declared'][1]; r['mailbox_capacity'][0] < r['mailbox_capacity'][1]; r['sequence_dependency'][0] <= r['sequence_dependency'][1]. Extra tracing fields are ignored; validation does not mutate the record.","evaluation_group":"xd-workflow-signal","failed_approach":"Adding the signal identity check repairs the reported defect, but replacing the adjacent recipient run check loses that independent invariant.","family":"xd-workflow-signal-signal_identity","id":"FA-1176","implementations":{"attempt":{"sha256":"bfca2c66afae4b0a7dac14c0b3dd7c190e5e1949f8016e30238fa9cf3902568f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(r):\n    return (r['signal_identity'][0] not in r['signal_identity'][1]) and (r['signal_declared'][0] in r['signal_declared'][1]) and (r['mailbox_capacity'][0] < r['mailbox_capacity'][1]) and (r['sequence_dependency'][0] <= r['sequence_dependency'][1])\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nr = {'signal_identity': ['s2', ['s1']], 'recipient_run': ['run2', 'run2'], 'signal_declared': ['approve', ['approve', 'reject']], 'mailbox_capacity': [9, 10], 'sequence_dependency': [4, 4]}\ncheck('valid operation', solve(r), True)\ncheck('Duplicate signal delivery applies the external command twice', solve(dict(r, **{'signal_identity': ['s1', ['s1']]})), False)\ncheck('A delayed signal reaches a different run under the same workflow name', solve(dict(r, **{'recipient_run': ['run1', 'run2']})), False)\ncheck('An unknown signal type bypasses workflow dispatch', solve(dict(r, **{'signal_declared': ['delete', ['approve', 'reject']]})), False)\ncheck('External signals exhaust the workflow pending-event budget', solve(dict(r, **{'mailbox_capacity': [10, 10]})), False)\ncheck('A signal is applied before its required earlier command', solve(dict(r, **{'sequence_dependency': [5, 4]})), False)\ncheck('unrelated tracing metadata', solve(dict(r, trace='run-'+str(N))), True)\ncheck('repeat validation is pure', solve(r), True)\ninvalid = {'signal_identity': ['s1', ['s1']], 'recipient_run': ['run1', 'run2'], 'signal_declared': ['delete', ['approve', 'reject']], 'mailbox_capacity': [10, 10], 'sequence_dependency': [5, 4]}\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":"5949dfc4fdd796e03f978bc39748d9b9fb25521a1a2e6ad23cef1a61d7a07c4d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(r):\n    return (r['recipient_run'][0] == r['recipient_run'][1]) and (r['signal_declared'][0] in r['signal_declared'][1]) and (r['mailbox_capacity'][0] < r['mailbox_capacity'][1]) and (r['sequence_dependency'][0] <= r['sequence_dependency'][1])\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nr = {'signal_identity': ['s2', ['s1']], 'recipient_run': ['run2', 'run2'], 'signal_declared': ['approve', ['approve', 'reject']], 'mailbox_capacity': [9, 10], 'sequence_dependency': [4, 4]}\ncheck('valid operation', solve(r), True)\ncheck('Duplicate signal delivery applies the external command twice', solve(dict(r, **{'signal_identity': ['s1', ['s1']]})), False)\ncheck('A delayed signal reaches a different run under the same workflow name', solve(dict(r, **{'recipient_run': ['run1', 'run2']})), False)\ncheck('An unknown signal type bypasses workflow dispatch', solve(dict(r, **{'signal_declared': ['delete', ['approve', 'reject']]})), False)\ncheck('External signals exhaust the workflow pending-event budget', solve(dict(r, **{'mailbox_capacity': [10, 10]})), False)\ncheck('A signal is applied before its required earlier command', solve(dict(r, **{'sequence_dependency': [5, 4]})), False)\ncheck('unrelated tracing metadata', solve(dict(r, trace='run-'+str(N))), True)\ncheck('repeat validation is pure', solve(r), True)\ninvalid = {'signal_identity': ['s1', ['s1']], 'recipient_run': ['run1', 'run2'], 'signal_declared': ['delete', ['approve', 'reject']], 'mailbox_capacity': [10, 10], 'sequence_dependency': [5, 4]}\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":"fd3de3ff0b482c3432a6355efa119d29aa1daa70ee3ac6574465788eecef7bca","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(r):\n    return (r['signal_identity'][0] not in r['signal_identity'][1]) and (r['recipient_run'][0] == r['recipient_run'][1]) and (r['signal_declared'][0] in r['signal_declared'][1]) and (r['mailbox_capacity'][0] < r['mailbox_capacity'][1]) and (r['sequence_dependency'][0] <= r['sequence_dependency'][1])\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nr = {'signal_identity': ['s2', ['s1']], 'recipient_run': ['run2', 'run2'], 'signal_declared': ['approve', ['approve', 'reject']], 'mailbox_capacity': [9, 10], 'sequence_dependency': [4, 4]}\ncheck('valid operation', solve(r), True)\ncheck('Duplicate signal delivery applies the external command twice', solve(dict(r, **{'signal_identity': ['s1', ['s1']]})), False)\ncheck('A delayed signal reaches a different run under the same workflow name', solve(dict(r, **{'recipient_run': ['run1', 'run2']})), False)\ncheck('An unknown signal type bypasses workflow dispatch', solve(dict(r, **{'signal_declared': ['delete', ['approve', 'reject']]})), False)\ncheck('External signals exhaust the workflow pending-event budget', solve(dict(r, **{'mailbox_capacity': [10, 10]})), False)\ncheck('A signal is applied before its required earlier command', solve(dict(r, **{'sequence_dependency': [5, 4]})), False)\ncheck('unrelated tracing metadata', solve(dict(r, trace='run-'+str(N))), True)\ncheck('repeat validation is pure', solve(r), True)\ninvalid = {'signal_identity': ['s1', ['s1']], 'recipient_run': ['run1', 'run2'], 'signal_declared': ['delete', ['approve', 'reject']], 'mailbox_capacity': [10, 10], 'sequence_dependency': [5, 4]}\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-workflow-signal-signal_identity","generated_at":"2026-09-29T14:36:59.423900+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['signal_identity'][0] not in r['signal_identity'][1] together with every other stated precondition before accepting the operation.","root_cause":"The admission path omits the signal identity invariant while validating the other operation preconditions.","sha256":"31a3a6c41df9f73ea30fa692b2d2d7349f9ed2a276539c9e9cb005aee5c08281","title":"Deliver a signal to a durable workflow: Duplicate signal delivery applies the external command twice · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":34.076,"exit_code":1,"observations":[{"actual":true,"check":"valid operation","expected":true,"passed":true},{"actual":false,"check":"Duplicate signal delivery applies the external command twice","expected":false,"passed":true},{"actual":true,"check":"A delayed signal reaches a different run under the same workflow name","expected":false,"passed":false},{"actual":false,"check":"An unknown signal type bypasses workflow dispatch","expected":false,"passed":true},{"actual":false,"check":"External signals exhaust the workflow pending-event budget","expected":false,"passed":true},{"actual":false,"check":"A signal is applied before its required earlier command","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\": \"Duplicate signal delivery applies the external command twice\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A delayed signal reaches a different run under the same workflow name\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"An unknown signal type bypasses workflow dispatch\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"External signals exhaust the workflow pending-event budget\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A signal is applied before its required earlier command\", \"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":39.782,"exit_code":1,"observations":[{"actual":true,"check":"valid operation","expected":true,"passed":true},{"actual":true,"check":"Duplicate signal delivery applies the external command twice","expected":false,"passed":false},{"actual":false,"check":"A delayed signal reaches a different run under the same workflow name","expected":false,"passed":true},{"actual":false,"check":"An unknown signal type bypasses workflow dispatch","expected":false,"passed":true},{"actual":false,"check":"External signals exhaust the workflow pending-event budget","expected":false,"passed":true},{"actual":false,"check":"A signal is applied before its required earlier command","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\": \"Duplicate signal delivery applies the external command twice\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"A delayed signal reaches a different run under the same workflow name\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"An unknown signal type bypasses workflow dispatch\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"External signals exhaust the workflow pending-event budget\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A signal is applied before its required earlier command\", \"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":125.179,"exit_code":0,"observations":[{"actual":true,"check":"valid operation","expected":true,"passed":true},{"actual":false,"check":"Duplicate signal delivery applies the external command twice","expected":false,"passed":true},{"actual":false,"check":"A delayed signal reaches a different run under the same workflow name","expected":false,"passed":true},{"actual":false,"check":"An unknown signal type bypasses workflow dispatch","expected":false,"passed":true},{"actual":false,"check":"External signals exhaust the workflow pending-event budget","expected":false,"passed":true},{"actual":false,"check":"A signal is applied before its required earlier command","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\": \"Duplicate signal delivery applies the external command twice\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A delayed signal reaches a different run under the same workflow name\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"An unknown signal type bypasses workflow dispatch\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"External signals exhaust the workflow pending-event budget\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"A signal is applied before its required earlier command\", \"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"}