{"abstract":"different fixed dimensions pass shard compatibility.","category":"Checkpoint tensor mapping","checks":6,"contract":"Return True when all non-scalar shapes have equal rank, nonnegative axis, and equal dimensions except along axis; empty input is False.","contract_signature":"shapes, axis","evaluation_group":"w3-checkpoint-tensor-mapping-axis-compatibility","failed_approach":"Modulo-normalizing an invalid axis turns it into a valid dimension.","family":"w3-checkpoint-tensor-mapping-axis-compatibility","id":"FA-99181","implementations":{"attempt":{"sha256":"717cabef3eef20e3ff39bea040647daebca1f3748cd21932b8b1d47ebf97c4c5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(shapes, axis):\n    return bool(shapes) and all(len(s)>0 and len(s)==len(shapes[0]) and all(s[i]==shapes[0][i] for i in range(len(s)) if i!=axis%len(s)) for s in shapes)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('valid', solve(*([[3, 2], [3, 4]], 1)), True)\ncheck('wrong fixed', solve(*([[3, 2], [4, 4]], 1)), False)\ncheck('negative axis', solve(*([[3], [3]], -1)), False)\ncheck('too large', solve(*([[3], [3]], 1)), False)\ncheck('empty', solve(*([], 0)), False)\ncheck('scalar shapes', solve(*([[], []], 0)), False)\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":"cc520a14edf68bec6652813539516f620eef0df8e159115a0bed1e108e1984cd","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(shapes, axis):\n    return bool(shapes) and all(len(s)==len(shapes[0]) for s in shapes)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('valid', solve(*([[3, 2], [3, 4]], 1)), True)\ncheck('wrong fixed', solve(*([[3, 2], [4, 4]], 1)), False)\ncheck('negative axis', solve(*([[3], [3]], -1)), False)\ncheck('too large', solve(*([[3], [3]], 1)), False)\ncheck('empty', solve(*([], 0)), False)\ncheck('scalar shapes', solve(*([[], []], 0)), False)\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 already decoded Python values; this toy contract makes no claim about a framework, file format, or production checkpoint. 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-checkpoint-tensor-mapping-axis-compatibility","generated_at":"2026-09-30T16:48:21.243593+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A bounded offline model of checkpoint tensor bookkeeping in a training workflow.","root_cause":"Rank equality is mistaken for shape compatibility.","sha256":"c1982d770dbf9d164fe817c7fa59e22717a835386b2fa33f522a3a9dbcd765cc","title":"Checkpoint mapping: different fixed dimensions pass shard compatibility · 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":28.076,"exit_code":1,"observations":[{"actual":true,"check":"valid","expected":true,"passed":true},{"actual":false,"check":"wrong fixed","expected":false,"passed":true},{"actual":true,"check":"negative axis","expected":false,"passed":false},{"actual":true,"check":"too large","expected":false,"passed":false},{"actual":false,"check":"empty","expected":false,"passed":true},{"actual":false,"check":"scalar shapes","expected":false,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"valid\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"wrong fixed\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"negative axis\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"too large\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"empty\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"scalar shapes\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":27.761,"exit_code":1,"observations":[{"actual":true,"check":"valid","expected":true,"passed":true},{"actual":true,"check":"wrong fixed","expected":false,"passed":false},{"actual":true,"check":"negative axis","expected":false,"passed":false},{"actual":true,"check":"too large","expected":false,"passed":false},{"actual":false,"check":"empty","expected":false,"passed":true},{"actual":true,"check":"scalar shapes","expected":false,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"valid\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"wrong fixed\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"negative axis\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"too large\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"empty\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"scalar shapes\", \"actual\": true, \"expected\": false, \"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."}}