{"abstract":"The operation returns a result or retained state that violates this contract: Emit n cyclic values from a finite input, or no values for empty input.","category":"Iterator consumption","checks":4,"contract":"Emit n cyclic values from a finite input, or no values for empty input. Inputs are the finite Python values shown by the executable fixtures; no concurrent execution is assumed.","contract_signature":"x, y=None","evaluation_group":"model-7ca535a8b8d19f97","failed_approach":"Repeating only the first item loses the rest of the cyclic order.","family":"xr-cycle-caches-entire-first-pass","id":"FA-4581","implementations":{"attempt":{"sha256":"661e24b60723172d44f0819ce698cf9983abb5faac859644d16a8ed21cb00e8a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport itertools as it\nfrom collections import deque\nN = 1\nobservations = []\ndef solve(x, y=None):\n    return (x[:1]*y)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('cycles order', solve(['a', 'b'], 5), ['a', 'b', 'a', 'b', 'a'])\ncheck('partial cycle', solve(['a', 'b', 'c'], 2), ['a', 'b'])\ncheck('empty input', solve([], 3), [])\ncheck('zero requested', solve(['a'], 0), [])\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":"16f8ff8ed05fcffe3b3a86f536f2ce4ef532ea6cab8f64e0e8e38e49d3c33af6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport itertools as it\nfrom collections import deque\nN = 1\nobservations = []\ndef solve(x, y=None):\n    return (x*y)[:len(x)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('cycles order', solve(['a', 'b'], 5), ['a', 'b', 'a', 'b', 'a'])\ncheck('partial cycle', solve(['a', 'b', 'c'], 2), ['a', 'b'])\ncheck('empty input', solve([], 3), [])\ncheck('zero requested', solve(['a'], 0), [])\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":"xr-cycle-caches-entire-first-pass","generated_at":"2026-09-29T14:37:40.808203+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A controlled local-runtime regression for collection APIs, language semantics, or ownership wrappers. Fixtures include boundary and interaction cases.","root_cause":"The output is capped at source length rather than requested length.","sha256":"577f0f7c2fbb37094b7cead0074bf8cbbd3db3a637bea88ed71ee482be7be234","title":"Cycle caches entire first pass · case 01","variant":1,"variant_policy":"Five execution reruns of a fixed adversarial fixture suite; variant number does not alter semantic inputs.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":38.007,"exit_code":1,"observations":[{"actual":["a","a","a","a","a"],"check":"cycles order","expected":["a","b","a","b","a"],"passed":false},{"actual":["a","a"],"check":"partial cycle","expected":["a","b"],"passed":false},{"actual":[],"check":"empty input","expected":[],"passed":true},{"actual":[],"check":"zero requested","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"cycles order\", \"actual\": [\"a\", \"a\", \"a\", \"a\", \"a\"], \"expected\": [\"a\", \"b\", \"a\", \"b\", \"a\"], \"passed\": false}, {\"check\": \"partial cycle\", \"actual\": [\"a\", \"a\"], \"expected\": [\"a\", \"b\"], \"passed\": false}, {\"check\": \"empty input\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"zero requested\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":36.852,"exit_code":1,"observations":[{"actual":["a","b"],"check":"cycles order","expected":["a","b","a","b","a"],"passed":false},{"actual":["a","b","c"],"check":"partial cycle","expected":["a","b"],"passed":false},{"actual":[],"check":"empty input","expected":[],"passed":true},{"actual":[],"check":"zero requested","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"cycles order\", \"actual\": [\"a\", \"b\"], \"expected\": [\"a\", \"b\", \"a\", \"b\", \"a\"], \"passed\": false}, {\"check\": \"partial cycle\", \"actual\": [\"a\", \"b\", \"c\"], \"expected\": [\"a\", \"b\"], \"passed\": false}, {\"check\": \"empty input\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"zero requested\", \"actual\": [], \"expected\": [], \"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."}}