{"abstract":"A failed flush marks its cache entry clean.","category":"Caching","checks":4,"contract":"Entry is [key,value,dirty]. Successful flush clears dirty; failed flush preserves prior dirty state and never changes key/value.","evaluation_group":"xc-failed-writeback-retains-dirty","failed_approach":"Making every failed flush dirty invents pending writes on clean entries.","family":"xc-failed-writeback-retains-dirty","id":"FA-10441","implementations":{"attempt":{"sha256":"8c1079997f716d9ef060c2fb607fe5e51d80d3ed566cd1c1495897954172d1b6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(entry, success):\n    return [entry[0],entry[1],not success]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*(['a', 3, True], False)), ['a', 3, True])\ncheck('fixture 2', solve(*(['a', 3, True], True)), ['a', 3, False])\ncheck('fixture 3', solve(*(['a', 3, False], False)), ['a', 3, False])\ncheck('fixture 4', solve(*(['a', None, False], True)), ['a', None, 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":"4e5146af508d594a6be4871dcf4fab06f183bee4a85fea34ad1cdb3fe6bdb993","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(entry, success):\n    return [entry[0],entry[1],False]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*(['a', 3, True], False)), ['a', 3, True])\ncheck('fixture 2', solve(*(['a', 3, True], True)), ['a', 3, False])\ncheck('fixture 3', solve(*(['a', 3, False], False)), ['a', 3, False])\ncheck('fixture 4', solve(*(['a', None, False], True)), ['a', None, 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":"3fdb86bf211218154d9691e476d7f7222d3ee4a5a1b46e1a4ff53de381faefd1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(entry, success):\n    return [entry[0],entry[1],entry[2] and not success]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*(['a', 3, True], False)), ['a', 3, True])\ncheck('fixture 2', solve(*(['a', 3, True], True)), ['a', 3, False])\ncheck('fixture 3', solve(*(['a', 3, False], False)), ['a', 3, False])\ncheck('fixture 4', solve(*(['a', None, False], True)), ['a', None, 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":"xc-failed-writeback-retains-dirty","generated_at":"2026-09-29T14:38:39.054762+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic cache state transformation. Inputs are copied or treated as immutable; no remote storage, real clock, or concurrent interleaving is simulated.","repair":"Preserve the cache-state invariant: Entry is [key,value,dirty]. Successful flush clears dirty; failed flush preserves prior dirty state and never changes key/value.","root_cause":"Dirty state is cleared at writeback attempt rather than successful completion.","sha256":"6b8fa4738500e0c4a490ac5963f1de5aaee9518747f63912c8b0820315786a68","title":"A failed flush marks its cache entry clean · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":41.151,"exit_code":1,"observations":[{"actual":["a",3,true],"check":"fixture 1","expected":["a",3,true],"passed":true},{"actual":["a",3,false],"check":"fixture 2","expected":["a",3,false],"passed":true},{"actual":["a",3,true],"check":"fixture 3","expected":["a",3,false],"passed":false},{"actual":["a",null,false],"check":"fixture 4","expected":["a",null,false],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [\"a\", 3, true], \"expected\": [\"a\", 3, true], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [\"a\", 3, false], \"expected\": [\"a\", 3, false], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [\"a\", 3, true], \"expected\": [\"a\", 3, false], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [\"a\", null, false], \"expected\": [\"a\", null, false], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":36.796,"exit_code":1,"observations":[{"actual":["a",3,false],"check":"fixture 1","expected":["a",3,true],"passed":false},{"actual":["a",3,false],"check":"fixture 2","expected":["a",3,false],"passed":true},{"actual":["a",3,false],"check":"fixture 3","expected":["a",3,false],"passed":true},{"actual":["a",null,false],"check":"fixture 4","expected":["a",null,false],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [\"a\", 3, false], \"expected\": [\"a\", 3, true], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [\"a\", 3, false], \"expected\": [\"a\", 3, false], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [\"a\", 3, false], \"expected\": [\"a\", 3, false], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"a\", null, false], \"expected\": [\"a\", null, false], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":43.165,"exit_code":0,"observations":[{"actual":["a",3,true],"check":"fixture 1","expected":["a",3,true],"passed":true},{"actual":["a",3,false],"check":"fixture 2","expected":["a",3,false],"passed":true},{"actual":["a",3,false],"check":"fixture 3","expected":["a",3,false],"passed":true},{"actual":["a",null,false],"check":"fixture 4","expected":["a",null,false],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [\"a\", 3, true], \"expected\": [\"a\", 3, true], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [\"a\", 3, false], \"expected\": [\"a\", 3, false], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [\"a\", 3, false], \"expected\": [\"a\", 3, false], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"a\", null, false], \"expected\": [\"a\", null, false], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}