{"abstract":"Track-level deduplication collapses independently queued occurrences.","category":"Media playlist state","checks":4,"contract":"Return the first occurrence of each unique entry ID in original first-occurrence order; track IDs may repeat and later duplicate-entry payloads are ignored.","contract_signature":"entries","evaluation_group":"xmed-playlist-deduplicate-entry-not-track","failed_approach":"Dictionary overwrite keeps later duplicate payloads instead of first occurrence.","family":"xmed-playlist-deduplicate-entry-not-track","id":"FA-11091","implementations":{"attempt":{"sha256":"8cd0149a5897b9c6f6010353a5996e93676bd3e14123110afe3fdd68abb9e34e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(entries):\n    return list({x[0]:x for x in entries}.values())\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([['a', 'first'], ['b', 'same'], ['a', 'later'], ['c', 'same']],)),[['a', 'first'], ['b', 'same'], ['c', 'same']])\ncheck('fixture 2',solve(*([],)),[])\ncheck('fixture 3',solve(*([['a', 'x']],)),[['a', 'x']])\ncheck('fixture 4',solve(*([['a', 'x'], ['b', 'x']],)),[['a', 'x'], ['b', 'x']])\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":"6a73e0ef377a618db31b8db96a970aecabbfc9ea9c678e2f153234f0a32f94c8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(entries):\n    return list({x[1]:x for x in entries}.values())\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([['a', 'first'], ['b', 'same'], ['a', 'later'], ['c', 'same']],)),[['a', 'first'], ['b', 'same'], ['c', 'same']])\ncheck('fixture 2',solve(*([],)),[])\ncheck('fixture 3',solve(*([['a', 'x']],)),[['a', 'x']])\ncheck('fixture 4',solve(*([['a', 'x'], ['b', 'x']],)),[['a', 'x'], ['b', 'x']])\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-playlist-deduplicate-entry-not-track","generated_at":"2026-09-29T14:38:44.915959+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":"Track-level deduplication collapses independently queued occurrences.","sha256":"815d6528eaec3ac095dea2dff00dfadecec18f1ba81c26cce47d06fca56c13b1","title":"Playlist deduplicate entry not track · 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":40.037,"exit_code":1,"observations":[{"actual":[["a","later"],["b","same"],["c","same"]],"check":"fixture 1","expected":[["a","first"],["b","same"],["c","same"]],"passed":false},{"actual":[],"check":"fixture 2","expected":[],"passed":true},{"actual":[["a","x"]],"check":"fixture 3","expected":[["a","x"]],"passed":true},{"actual":[["a","x"],["b","x"]],"check":"fixture 4","expected":[["a","x"],["b","x"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[\"a\", \"later\"], [\"b\", \"same\"], [\"c\", \"same\"]], \"expected\": [[\"a\", \"first\"], [\"b\", \"same\"], [\"c\", \"same\"]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[\"a\", \"x\"]], \"expected\": [[\"a\", \"x\"]], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[\"a\", \"x\"], [\"b\", \"x\"]], \"expected\": [[\"a\", \"x\"], [\"b\", \"x\"]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.417,"exit_code":1,"observations":[{"actual":[["a","first"],["c","same"],["a","later"]],"check":"fixture 1","expected":[["a","first"],["b","same"],["c","same"]],"passed":false},{"actual":[],"check":"fixture 2","expected":[],"passed":true},{"actual":[["a","x"]],"check":"fixture 3","expected":[["a","x"]],"passed":true},{"actual":[["b","x"]],"check":"fixture 4","expected":[["a","x"],["b","x"]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[\"a\", \"first\"], [\"c\", \"same\"], [\"a\", \"later\"]], \"expected\": [[\"a\", \"first\"], [\"b\", \"same\"], [\"c\", \"same\"]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[\"a\", \"x\"]], \"expected\": [[\"a\", \"x\"]], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[\"b\", \"x\"]], \"expected\": [[\"a\", \"x\"], [\"b\", \"x\"]], \"passed\": false}], \"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."}}