{"abstract":"Completion of an old flush clears a newer dirty update.","category":"Caching","checks":4,"contract":"Entry is [key,value,version,dirty]. Clear dirty only when flush succeeded for this exact current version; preserve all other fields.","evaluation_group":"xc-writeback-version-match","failed_approach":"Matching versions clear dirty even when persistence failed.","family":"xc-writeback-version-match","id":"FA-10446","implementations":{"attempt":{"sha256":"ca5a3e836fc71eb6b65f190ceef88d92bd24cde036f3b72073106fdd2aa924f6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(entry, flushed_version, success):\n    return [entry[0],entry[1],entry[2],entry[3] and entry[2]!=flushed_version]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*(['a', 'new', 2, True], 1, True)), ['a', 'new', 2, True])\ncheck('fixture 2', solve(*(['a', 'new', 2, True], 2, False)), ['a', 'new', 2, True])\ncheck('fixture 3', solve(*(['a', 'new', 2, True], 2, True)), ['a', 'new', 2, False])\ncheck('fixture 4', solve(*(['a', 'new', 2, False], 1, False)), ['a', 'new', 2, 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":"58cff6f8e1b9555f6412a1dd9f9b49103b65550b608f693db2d367ef4497f4e8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(entry, flushed_version, success):\n    return [entry[0],entry[1],entry[2],False if success else entry[3]]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*(['a', 'new', 2, True], 1, True)), ['a', 'new', 2, True])\ncheck('fixture 2', solve(*(['a', 'new', 2, True], 2, False)), ['a', 'new', 2, True])\ncheck('fixture 3', solve(*(['a', 'new', 2, True], 2, True)), ['a', 'new', 2, False])\ncheck('fixture 4', solve(*(['a', 'new', 2, False], 1, False)), ['a', 'new', 2, 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":"62ee51428ce31f373073ad96001c8c2a368f5e4f85e78560b1b937c31edfb0cc","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(entry, flushed_version, success):\n    return [entry[0],entry[1],entry[2],entry[3] and not (success and entry[2]==flushed_version)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*(['a', 'new', 2, True], 1, True)), ['a', 'new', 2, True])\ncheck('fixture 2', solve(*(['a', 'new', 2, True], 2, False)), ['a', 'new', 2, True])\ncheck('fixture 3', solve(*(['a', 'new', 2, True], 2, True)), ['a', 'new', 2, False])\ncheck('fixture 4', solve(*(['a', 'new', 2, False], 1, False)), ['a', 'new', 2, 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-writeback-version-match","generated_at":"2026-09-29T14:38:39.100564+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,version,dirty]. Clear dirty only when flush succeeded for this exact current version; preserve all other fields.","root_cause":"Flush completion has no version comparison with the currently cached write.","sha256":"7833e6abe03e1ebedeac6dad8272555ae0c162551f83d9b913fb0063d6967503","title":"Completion of an old flush clears a newer dirty update · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":45.169,"exit_code":1,"observations":[{"actual":["a","new",2,true],"check":"fixture 1","expected":["a","new",2,true],"passed":true},{"actual":["a","new",2,false],"check":"fixture 2","expected":["a","new",2,true],"passed":false},{"actual":["a","new",2,false],"check":"fixture 3","expected":["a","new",2,false],"passed":true},{"actual":["a","new",2,false],"check":"fixture 4","expected":["a","new",2,false],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [\"a\", \"new\", 2, true], \"expected\": [\"a\", \"new\", 2, true], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [\"a\", \"new\", 2, false], \"expected\": [\"a\", \"new\", 2, true], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [\"a\", \"new\", 2, false], \"expected\": [\"a\", \"new\", 2, false], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"a\", \"new\", 2, false], \"expected\": [\"a\", \"new\", 2, false], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.44,"exit_code":1,"observations":[{"actual":["a","new",2,false],"check":"fixture 1","expected":["a","new",2,true],"passed":false},{"actual":["a","new",2,true],"check":"fixture 2","expected":["a","new",2,true],"passed":true},{"actual":["a","new",2,false],"check":"fixture 3","expected":["a","new",2,false],"passed":true},{"actual":["a","new",2,false],"check":"fixture 4","expected":["a","new",2,false],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [\"a\", \"new\", 2, false], \"expected\": [\"a\", \"new\", 2, true], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [\"a\", \"new\", 2, true], \"expected\": [\"a\", \"new\", 2, true], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [\"a\", \"new\", 2, false], \"expected\": [\"a\", \"new\", 2, false], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"a\", \"new\", 2, false], \"expected\": [\"a\", \"new\", 2, false], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.695,"exit_code":0,"observations":[{"actual":["a","new",2,true],"check":"fixture 1","expected":["a","new",2,true],"passed":true},{"actual":["a","new",2,true],"check":"fixture 2","expected":["a","new",2,true],"passed":true},{"actual":["a","new",2,false],"check":"fixture 3","expected":["a","new",2,false],"passed":true},{"actual":["a","new",2,false],"check":"fixture 4","expected":["a","new",2,false],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [\"a\", \"new\", 2, true], \"expected\": [\"a\", \"new\", 2, true], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [\"a\", \"new\", 2, true], \"expected\": [\"a\", \"new\", 2, true], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [\"a\", \"new\", 2, false], \"expected\": [\"a\", \"new\", 2, false], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"a\", \"new\", 2, false], \"expected\": [\"a\", \"new\", 2, false], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}