{"abstract":"Flattened packed tokens retain the wrong owner indices.","category":"Sequence batch packing","checks":6,"contract":"Flatten sequences in order and return parallel zero-based sequence-owner IDs for every token.","contract_signature":"sequences","evaluation_group":"w3-seqpack-flat-owner-v1","failed_approach":"Dropping the final owner marker per sequence only passes for empty inputs.","family":"w3-sequence-batch-packing-pack-token-ownership","id":"FA-98131","implementations":{"attempt":{"sha256":"2bb49053f22b86cc16a51a274d8bd386fa481e1477e3da473120469472294e32","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(sequences):\n    return [x for s in sequences for x in s], [i for i,s in enumerate(sequences) for _ in range(max(0,len(s)-1))]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\na=[N,2]; b=[3]*N\ncheck('ownership lengths', solve([a,b]), (a+b,[0]*2+[1]*N))\ncheck('empty', solve([]), ([],[]))\ncheck('empty segment', solve([[],[7]]), ([7],[1]))\ncheck('single segment', solve([[N]*N]), ([N]*N,[0]*N))\ncheck('three owners', solve([[1],[2,3],[4]]), ([1,2,3,4],[0,1,1,2]))\ncheck('equal values', solve([[1],[1]]), ([1,1],[0,1]))\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":"a13207a23677af110145e36acd7f6c704c0f3185b07702a6f24502984a808468","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(sequences):\n    return [x for s in sequences for x in s], [i+1 for i,s in enumerate(sequences) for _ in s]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\na=[N,2]; b=[3]*N\ncheck('ownership lengths', solve([a,b]), (a+b,[0]*2+[1]*N))\ncheck('empty', solve([]), ([],[]))\ncheck('empty segment', solve([[],[7]]), ([7],[1]))\ncheck('single segment', solve([[N]*N]), ([N]*N,[0]*N))\ncheck('three owners', solve([[1],[2,3],[4]]), ([1,2,3,4],[0,1,1,2]))\ncheck('equal values', solve([[1],[1]]), ([1,1],[0,1]))\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 short integer-token lists under the stated toy contract; results do not claim compatibility with a specific training framework. 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-sequence-batch-packing-pack-token-ownership","generated_at":"2026-09-30T16:48:09.757740+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic toy packing rule models a common boundary in preparing bounded training sequences.","root_cause":"Owner IDs are shifted to one-based values and can mismatch other row-local metadata.","sha256":"5a1c7a9f7c79cf7f5166b83a498e637c69326c3be3abfcff0ea7aab560d23c26","title":"Flattened packed tokens retain the wrong owner indices · case 01","variant":1,"variant_policy":"The fixture code references N, supplied as 1 through 5. Fixed boundary checks may repeat. These records share one mechanism and must remain together in evaluation splits.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":27.996,"exit_code":1,"observations":[{"actual":[[1,2,3],[0]],"check":"ownership lengths","expected":[[1,2,3],[0,0,1]],"passed":false},{"actual":[[],[]],"check":"empty","expected":[[],[]],"passed":true},{"actual":[[7],[]],"check":"empty segment","expected":[[7],[1]],"passed":false},{"actual":[[1],[]],"check":"single segment","expected":[[1],[0]],"passed":false},{"actual":[[1,2,3,4],[1]],"check":"three owners","expected":[[1,2,3,4],[0,1,1,2]],"passed":false},{"actual":[[1,1],[]],"check":"equal values","expected":[[1,1],[0,1]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"ownership lengths\", \"actual\": [[1, 2, 3], [0]], \"expected\": [[1, 2, 3], [0, 0, 1]], \"passed\": false}, {\"check\": \"empty\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}, {\"check\": \"empty segment\", \"actual\": [[7], []], \"expected\": [[7], [1]], \"passed\": false}, {\"check\": \"single segment\", \"actual\": [[1], []], \"expected\": [[1], [0]], \"passed\": false}, {\"check\": \"three owners\", \"actual\": [[1, 2, 3, 4], [1]], \"expected\": [[1, 2, 3, 4], [0, 1, 1, 2]], \"passed\": false}, {\"check\": \"equal values\", \"actual\": [[1, 1], []], \"expected\": [[1, 1], [0, 1]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":26.58,"exit_code":1,"observations":[{"actual":[[1,2,3],[1,1,2]],"check":"ownership lengths","expected":[[1,2,3],[0,0,1]],"passed":false},{"actual":[[],[]],"check":"empty","expected":[[],[]],"passed":true},{"actual":[[7],[2]],"check":"empty segment","expected":[[7],[1]],"passed":false},{"actual":[[1],[1]],"check":"single segment","expected":[[1],[0]],"passed":false},{"actual":[[1,2,3,4],[1,2,2,3]],"check":"three owners","expected":[[1,2,3,4],[0,1,1,2]],"passed":false},{"actual":[[1,1],[1,2]],"check":"equal values","expected":[[1,1],[0,1]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"ownership lengths\", \"actual\": [[1, 2, 3], [1, 1, 2]], \"expected\": [[1, 2, 3], [0, 0, 1]], \"passed\": false}, {\"check\": \"empty\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}, {\"check\": \"empty segment\", \"actual\": [[7], [2]], \"expected\": [[7], [1]], \"passed\": false}, {\"check\": \"single segment\", \"actual\": [[1], [1]], \"expected\": [[1], [0]], \"passed\": false}, {\"check\": \"three owners\", \"actual\": [[1, 2, 3, 4], [1, 2, 2, 3]], \"expected\": [[1, 2, 3, 4], [0, 1, 1, 2]], \"passed\": false}, {\"check\": \"equal values\", \"actual\": [[1, 1], [1, 2]], \"expected\": [[1, 1], [0, 1]], \"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."}}