{"abstract":"Completion of an earlier seek overwrites the newer requested position.","category":"Media timeline seeking","checks":4,"contract":"Install an asynchronous seek result [generation,position] only if it belongs to the exact current seek request; retain current position otherwise.","contract_signature":"position, generation, completion","evaluation_group":"xmed-seek-request-generation-result","failed_approach":"Accepting all older generations preserves the race instead of fencing obsolete completions.","family":"xmed-seek-request-generation-result","id":"FA-11276","implementations":{"attempt":{"sha256":"89c738a2d9db535f6ff24d57120865a84503f81b2f86f6a60b1e8a9490fdf5d9","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(position, generation, completion):\n    return completion[1] if completion[0]<=generation else position\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(10, 3, [2, 2])),10)\ncheck('fixture 2',solve(*(10, 3, [3, 20])),20)\ncheck('fixture 3',solve(*(10, 3, [4, 30])),10)\ncheck('fixture 4',solve(*(0, 0, [0, 5])),5)\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":"993c4027e47eb3311147424e473c8764d27bfdcb8a367f32a81d9f89e3e2d3b6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(position, generation, completion):\n    return completion[1]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(10, 3, [2, 2])),10)\ncheck('fixture 2',solve(*(10, 3, [3, 20])),20)\ncheck('fixture 3',solve(*(10, 3, [4, 30])),10)\ncheck('fixture 4',solve(*(0, 0, [0, 5])),5)\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":"xmed-seek-request-generation-result","generated_at":"2026-09-29T14:38:46.551699+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic local media controller stage; metadata and downloaded data are supplied explicitly. No external player, service or codec is required.","root_cause":"Completion of an earlier seek overwrites the newer requested position.","sha256":"973191d6fae9dd793078830d583688753cbd40734d4d5b6e523626cb646f9570","title":"Seek request generation result · case 01","variant":1,"variant_policy":"The five numbered cases rerun the same authored boundary fixtures; they are reproducibility runs, not independent input variants.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":41.032,"exit_code":1,"observations":[{"actual":2,"check":"fixture 1","expected":10,"passed":false},{"actual":20,"check":"fixture 2","expected":20,"passed":true},{"actual":10,"check":"fixture 3","expected":10,"passed":true},{"actual":5,"check":"fixture 4","expected":5,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 2, \"expected\": 10, \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": 20, \"expected\": 20, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 10, \"expected\": 10, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 5, \"expected\": 5, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.009,"exit_code":1,"observations":[{"actual":2,"check":"fixture 1","expected":10,"passed":false},{"actual":20,"check":"fixture 2","expected":20,"passed":true},{"actual":30,"check":"fixture 3","expected":10,"passed":false},{"actual":5,"check":"fixture 4","expected":5,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 2, \"expected\": 10, \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": 20, \"expected\": 20, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 30, \"expected\": 10, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": 5, \"expected\": 5, \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}