{"abstract":"IDs from later partition manifests disappear.","category":"Dataset split isolation","checks":7,"contract":"Partitions map names to lists of string IDs; return the flattened IDs in partition/input order, with duplicates removed globally.","contract_signature":"partitions","evaluation_group":"ds-manifest-disjoint","failed_approach":"Removing only adjacent duplicates still repeats an ID that reappears after another ID.","family":"w3-dataset-split-isolation-partition-manifest-disjoint","id":"FA-97926","implementations":{"attempt":{"sha256":"5026040b9f5a5790758f7df0e0ed8dc4bd6003d4012e688fba4dd3c9a1bf0c82","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(partitions):\n    out=[]\n    for x in (x for values in partitions.values() for x in values):\n     if not out or out[-1]!=x: out.append(x)\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('overlap assigned once',solve({'train':['a','b'],'validation':['b','c']}),['a','b','c'])\ncheck('empty',solve({}),[])\ncheck('empty partition',solve({'train':[]}),[])\ncheck('within duplicate',solve({'train':['a','a']}),['a'])\ncheck('order stable',solve({'validation':['z'],'train':['a','z']}),['z','a'])\ncheck('three sides',solve({'a':['x'],'b':['y'],'c':['x','z']}),['x','y','z'])\ncheck('nonadjacent duplicate',solve({'train':['a','b'],'validation':['a']}),['a','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":"8faa883e9b92010388ccdd65a5554ddd1cede83e6acff46b193a34823020810a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(partitions):\n    return list(dict.fromkeys(next(iter(partitions.values()),[])))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('overlap assigned once',solve({'train':['a','b'],'validation':['b','c']}),['a','b','c'])\ncheck('empty',solve({}),[])\ncheck('empty partition',solve({'train':[]}),[])\ncheck('within duplicate',solve({'train':['a','a']}),['a'])\ncheck('order stable',solve({'validation':['z'],'train':['a','z']}),['z','a'])\ncheck('three sides',solve({'a':['x'],'b':['y'],'c':['x','z']}),['x','y','z'])\ncheck('nonadjacent duplicate',solve({'train':['a','b'],'validation':['a']}),['a','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":"Inputs are small in-memory records with self-contained contracts; no claim is made about production sampling quality. 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":"w3-dataset-split-isolation-partition-manifest-disjoint","generated_at":"2026-09-30T16:48:07.548583+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This toy split allocator makes membership rules explicit for reproducible evaluation fixtures.","root_cause":"The implementation returns only the first partition’s IDs, discarding all subsequent membership lists.","sha256":"bee5afccda17cd215d694eb2ea0e8c7cdde89f7f09aae02eafbaa78888f9613d","title":"Dataset split: IDs from later partition manifests disappear · case 01","variant":1,"variant_policy":"The same explicitly authored fixtures repeat across all five numbered records; runtime N is unused. These records share one mechanism and must remain together in evaluation splits.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":28.647,"exit_code":1,"observations":[{"actual":["a","b","c"],"check":"overlap assigned once","expected":["a","b","c"],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[],"check":"empty partition","expected":[],"passed":true},{"actual":["a"],"check":"within duplicate","expected":["a"],"passed":true},{"actual":["z","a","z"],"check":"order stable","expected":["z","a"],"passed":false},{"actual":["x","y","x","z"],"check":"three sides","expected":["x","y","z"],"passed":false},{"actual":["a","b","a"],"check":"nonadjacent duplicate","expected":["a","b"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"overlap assigned once\", \"actual\": [\"a\", \"b\", \"c\"], \"expected\": [\"a\", \"b\", \"c\"], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"empty partition\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"within duplicate\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"order stable\", \"actual\": [\"z\", \"a\", \"z\"], \"expected\": [\"z\", \"a\"], \"passed\": false}, {\"check\": \"three sides\", \"actual\": [\"x\", \"y\", \"x\", \"z\"], \"expected\": [\"x\", \"y\", \"z\"], \"passed\": false}, {\"check\": \"nonadjacent duplicate\", \"actual\": [\"a\", \"b\", \"a\"], \"expected\": [\"a\", \"b\"], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":27.986,"exit_code":1,"observations":[{"actual":["a","b"],"check":"overlap assigned once","expected":["a","b","c"],"passed":false},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[],"check":"empty partition","expected":[],"passed":true},{"actual":["a"],"check":"within duplicate","expected":["a"],"passed":true},{"actual":["z"],"check":"order stable","expected":["z","a"],"passed":false},{"actual":["x"],"check":"three sides","expected":["x","y","z"],"passed":false},{"actual":["a","b"],"check":"nonadjacent duplicate","expected":["a","b"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"overlap assigned once\", \"actual\": [\"a\", \"b\"], \"expected\": [\"a\", \"b\", \"c\"], \"passed\": false}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"empty partition\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"within duplicate\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"order stable\", \"actual\": [\"z\"], \"expected\": [\"z\", \"a\"], \"passed\": false}, {\"check\": \"three sides\", \"actual\": [\"x\"], \"expected\": [\"x\", \"y\", \"z\"], \"passed\": false}, {\"check\": \"nonadjacent duplicate\", \"actual\": [\"a\", \"b\"], \"expected\": [\"a\", \"b\"], \"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."}}