{"abstract":"Appending a refreshed manifest duplicates overlapping sequence numbers.","category":"Streaming segment lifecycle","checks":4,"contract":"Merge unique-per-input [integer media-sequence,payload] records by sequence; incoming revisions win, output is sequence ordered.","evaluation_group":"xmed-manifest-merge-by-sequence","failed_approach":"Keeping the prior payload loses revised metadata from the fresh manifest.","family":"xmed-manifest-merge-by-sequence","id":"FA-11106","implementations":{"attempt":{"sha256":"0a0e3257ba6cc48d8c860e844328424addeafb8bb7268faed7ab974b58bd80ac","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(old, incoming):\n    return [[k,v] for k,v in sorted(dict(list(incoming)+list(old)).items())]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[10, 'a'], [11, 'old']], [[11, 'new'], [12, 'c']])),[[10, 'a'], [11, 'new'], [12, 'c']])\ncheck('fixture 2',solve(*([], [[2, 'x']])),[[2, 'x']])\ncheck('fixture 3',solve(*([[1, 'x']], [])),[[1, 'x']])\ncheck('fixture 4',solve(*([[2, 'b']], [[1, 'a']])),[[1, 'a'], [2, 'b']])\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":"f125aa0fa484f9c008062e3d98bf653d58dd29f2c8ad2e786836177381e6c7e6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(old, incoming):\n    return list(old)+list(incoming)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[10, 'a'], [11, 'old']], [[11, 'new'], [12, 'c']])),[[10, 'a'], [11, 'new'], [12, 'c']])\ncheck('fixture 2',solve(*([], [[2, 'x']])),[[2, 'x']])\ncheck('fixture 3',solve(*([[1, 'x']], [])),[[1, 'x']])\ncheck('fixture 4',solve(*([[2, 'b']], [[1, 'a']])),[[1, 'a'], [2, 'b']])\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":"ee655ed0bebe2aba7b0d3adb755e4a925ff603bc13ab6623938d3ef9d9b19865","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(old, incoming):\n    return [[k,v] for k,v in sorted(dict(list(old)+list(incoming)).items())]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[10, 'a'], [11, 'old']], [[11, 'new'], [12, 'c']])),[[10, 'a'], [11, 'new'], [12, 'c']])\ncheck('fixture 2',solve(*([], [[2, 'x']])),[[2, 'x']])\ncheck('fixture 3',solve(*([[1, 'x']], [])),[[1, 'x']])\ncheck('fixture 4',solve(*([[2, 'b']], [[1, 'a']])),[[1, 'a'], [2, 'b']])\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-manifest-merge-by-sequence","generated_at":"2026-09-29T14:38:44.995182+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.","repair":"Preserve the media contract: Merge unique-per-input [integer media-sequence,payload] records by sequence; incoming revisions win, output is sequence ordered.","root_cause":"Appending a refreshed manifest duplicates overlapping sequence numbers.","sha256":"0c2ae292e9baa5268c874b738847bb891eea2051ee1b05e50a0c53d677e8e722","title":"Manifest merge by sequence · case 01","variant":1,"variant_policy":"The five numbered cases rerun the same authored boundary fixtures; they are reproducibility runs, not independent input variants.","verification":{"attempt":{"elapsed_ms":41.865,"exit_code":1,"observations":[{"actual":[[10,"a"],[11,"old"],[12,"c"]],"check":"fixture 1","expected":[[10,"a"],[11,"new"],[12,"c"]],"passed":false},{"actual":[[2,"x"]],"check":"fixture 2","expected":[[2,"x"]],"passed":true},{"actual":[[1,"x"]],"check":"fixture 3","expected":[[1,"x"]],"passed":true},{"actual":[[1,"a"],[2,"b"]],"check":"fixture 4","expected":[[1,"a"],[2,"b"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[10, \"a\"], [11, \"old\"], [12, \"c\"]], \"expected\": [[10, \"a\"], [11, \"new\"], [12, \"c\"]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[2, \"x\"]], \"expected\": [[2, \"x\"]], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[1, \"x\"]], \"expected\": [[1, \"x\"]], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[1, \"a\"], [2, \"b\"]], \"expected\": [[1, \"a\"], [2, \"b\"]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.27,"exit_code":1,"observations":[{"actual":[[10,"a"],[11,"old"],[11,"new"],[12,"c"]],"check":"fixture 1","expected":[[10,"a"],[11,"new"],[12,"c"]],"passed":false},{"actual":[[2,"x"]],"check":"fixture 2","expected":[[2,"x"]],"passed":true},{"actual":[[1,"x"]],"check":"fixture 3","expected":[[1,"x"]],"passed":true},{"actual":[[2,"b"],[1,"a"]],"check":"fixture 4","expected":[[1,"a"],[2,"b"]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[10, \"a\"], [11, \"old\"], [11, \"new\"], [12, \"c\"]], \"expected\": [[10, \"a\"], [11, \"new\"], [12, \"c\"]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[2, \"x\"]], \"expected\": [[2, \"x\"]], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[1, \"x\"]], \"expected\": [[1, \"x\"]], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[2, \"b\"], [1, \"a\"]], \"expected\": [[1, \"a\"], [2, \"b\"]], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.337,"exit_code":0,"observations":[{"actual":[[10,"a"],[11,"new"],[12,"c"]],"check":"fixture 1","expected":[[10,"a"],[11,"new"],[12,"c"]],"passed":true},{"actual":[[2,"x"]],"check":"fixture 2","expected":[[2,"x"]],"passed":true},{"actual":[[1,"x"]],"check":"fixture 3","expected":[[1,"x"]],"passed":true},{"actual":[[1,"a"],[2,"b"]],"check":"fixture 4","expected":[[1,"a"],[2,"b"]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[10, \"a\"], [11, \"new\"], [12, \"c\"]], \"expected\": [[10, \"a\"], [11, \"new\"], [12, \"c\"]], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [[2, \"x\"]], \"expected\": [[2, \"x\"]], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[1, \"x\"]], \"expected\": [[1, \"x\"]], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[1, \"a\"], [2, \"b\"]], \"expected\": [[1, \"a\"], [2, \"b\"]], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}