{"abstract":"partial tensor restoration copies the wrong interval.","category":"Checkpoint tensor mapping","checks":6,"contract":"Overlay source values into target beginning at start; preserve the rest, clipping at target end; invalid negative start returns [].","contract_signature":"target, source, start","evaluation_group":"w3-checkpoint-tensor-mapping-slice-overlap","failed_approach":"Clipping handles the right boundary but does not reject a negative destination index.","family":"w3-checkpoint-tensor-mapping-slice-overlap","id":"FA-99226","implementations":{"attempt":{"sha256":"9a8639d15c64540400179bcfaf4c2f38d64eac42e9fbc56e8c231fe2f83866e9","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(target, source, start):\n    out=target[:]\n    end=min(len(target),start+len(source))\n    out[start:end]=source[:end-start]\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('middle', solve(*([0, 0, 0, 0], [3, 2], 1)), [0, 3, 2, 0])\ncheck('at start', solve(*([0, 0], [3], 0)), [3, 0])\ncheck('clipped', solve(*([0, 0, 0], [3, 2, 3, 4], 2)), [0, 0, 3])\ncheck('empty source', solve(*([1, 2], [], 1)), [1, 2])\ncheck('empty target', solve(*([], [3], 0)), [])\ncheck('negative', solve(*([1], [3], -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":"1a89bff75805f6f88868a70ee8841f92782d7db14cb68ade9b697814fc0a87c6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(target, source, start):\n    out=target[:]\n    out[:min(len(source),len(target))]=source[:len(target)]\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('middle', solve(*([0, 0, 0, 0], [3, 2], 1)), [0, 3, 2, 0])\ncheck('at start', solve(*([0, 0], [3], 0)), [3, 0])\ncheck('clipped', solve(*([0, 0, 0], [3, 2, 3, 4], 2)), [0, 0, 3])\ncheck('empty source', solve(*([1, 2], [], 1)), [1, 2])\ncheck('empty target', solve(*([], [3], 0)), [])\ncheck('negative', solve(*([1], [3], -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 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-slice-overlap","generated_at":"2026-09-30T16:48:21.700575+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":"Restoration copies a prefix rather than the requested overlap window.","sha256":"65a11c483c574040fff23f3ccc787e5d671298ac61337187c1e3b4fb9ef3f16c","title":"Checkpoint mapping: partial tensor restoration copies the wrong interval · 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":28.641,"exit_code":1,"observations":[{"actual":[0,3,2,0],"check":"middle","expected":[0,3,2,0],"passed":true},{"actual":[3,0],"check":"at start","expected":[3,0],"passed":true},{"actual":[0,0,3],"check":"clipped","expected":[0,0,3],"passed":true},{"actual":[1,2],"check":"empty source","expected":[1,2],"passed":true},{"actual":[],"check":"empty target","expected":[],"passed":true},{"actual":[3,1],"check":"negative","expected":[],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"middle\", \"actual\": [0, 3, 2, 0], \"expected\": [0, 3, 2, 0], \"passed\": true}, {\"check\": \"at start\", \"actual\": [3, 0], \"expected\": [3, 0], \"passed\": true}, {\"check\": \"clipped\", \"actual\": [0, 0, 3], \"expected\": [0, 0, 3], \"passed\": true}, {\"check\": \"empty source\", \"actual\": [1, 2], \"expected\": [1, 2], \"passed\": true}, {\"check\": \"empty target\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"negative\", \"actual\": [3, 1], \"expected\": [], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":28.589,"exit_code":1,"observations":[{"actual":[3,2,0,0],"check":"middle","expected":[0,3,2,0],"passed":false},{"actual":[3,0],"check":"at start","expected":[3,0],"passed":true},{"actual":[3,2,3],"check":"clipped","expected":[0,0,3],"passed":false},{"actual":[1,2],"check":"empty source","expected":[1,2],"passed":true},{"actual":[],"check":"empty target","expected":[],"passed":true},{"actual":[3],"check":"negative","expected":[],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"middle\", \"actual\": [3, 2, 0, 0], \"expected\": [0, 3, 2, 0], \"passed\": false}, {\"check\": \"at start\", \"actual\": [3, 0], \"expected\": [3, 0], \"passed\": true}, {\"check\": \"clipped\", \"actual\": [3, 2, 3], \"expected\": [0, 0, 3], \"passed\": false}, {\"check\": \"empty source\", \"actual\": [1, 2], \"expected\": [1, 2], \"passed\": true}, {\"check\": \"empty target\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"negative\", \"actual\": [3], \"expected\": [], \"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."}}