{"abstract":"A stitched response exposes the oldest contributing fragment age.","category":"HTTP ranges","checks":6,"contract":"Return max fragment age plus elapsed, or elapsed for no fragments. Inputs nonnegative integer seconds.","evaluation_group":"s3-http_ranges-cache-assembly","failed_approach":"The partial repair uses return sum(ages)//len(ages)+elapsed if ages else elapsed, which still violates the stated contract.","family":"s3-http_ranges-cache-age-oldest-fragment","id":"FA-26511","implementations":{"attempt":{"sha256":"8988481c2ab295527dd12e88be8dca8f78eae76669255d7320435ed0f1bf45c0","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(ages, elapsed):\n    return sum(ages)//len(ages)+elapsed if ages else elapsed\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('cache-age-oldest-fragment fixture 0', solve([N,3*N],N), 4*N)\ncheck('cache-age-oldest-fragment fixture 1', solve([3*N,N],0), 3*N)\ncheck('cache-age-oldest-fragment fixture 2', solve([],N), N)\ncheck('cache-age-oldest-fragment fixture 3', solve([0,0],N), N)\ncheck('cache-age-oldest-fragment fixture 4', solve([N],N), 2*N)\ncheck('cache-age-oldest-fragment fixture 5', solve([0,N,0],0), N)\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":"9fe03f5b46127bc20cc80325b2681ddeffc88a49e0c0bc1b539afbcfdd6f0cef","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(ages, elapsed):\n    return min(ages,default=0)+elapsed\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('cache-age-oldest-fragment fixture 0', solve([N,3*N],N), 4*N)\ncheck('cache-age-oldest-fragment fixture 1', solve([3*N,N],0), 3*N)\ncheck('cache-age-oldest-fragment fixture 2', solve([],N), N)\ncheck('cache-age-oldest-fragment fixture 3', solve([0,0],N), N)\ncheck('cache-age-oldest-fragment fixture 4', solve([N],N), 2*N)\ncheck('cache-age-oldest-fragment fixture 5', solve([0,N,0],0), N)\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"},"fixed":{"sha256":"c9adfe8e6ecc5dda987ea5885f48be1c8e7ddce34489aebf0e38045c91d85aea","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(ages, elapsed):\n    return max(ages,default=0)+elapsed\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('cache-age-oldest-fragment fixture 0', solve([N,3*N],N), 4*N)\ncheck('cache-age-oldest-fragment fixture 1', solve([3*N,N],0), 3*N)\ncheck('cache-age-oldest-fragment fixture 2', solve([],N), N)\ncheck('cache-age-oldest-fragment fixture 3', solve([0,0],N), N)\ncheck('cache-age-oldest-fragment fixture 4', solve([N],N), 2*N)\ncheck('cache-age-oldest-fragment fixture 5', solve([0,N,0],0), N)\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":"Deterministic simplified range service, with stipulated local policies and already parsed trusted inputs; not a complete HTTP implementation. 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":"s3-http_ranges-cache-age-oldest-fragment","generated_at":"2026-09-29T14:41:16.696171+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Range responses combine representation identity, conditional requests, framing, and partial-object state.","repair":"Apply the bounded decision exactly: return max(ages,default=0)+elapsed","root_cause":"The cache-age-oldest-fragment decision uses return min(ages,default=0)+elapsed.","sha256":"ca5ceb83f1ccf76aef3d15073a2f404bdbacdb8e3918d549bb7d77ebe45c8df9","title":"A stitched response exposes the oldest contributing fragment age · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.201,"exit_code":1,"observations":[{"actual":3,"check":"cache-age-oldest-fragment fixture 0","expected":4,"passed":false},{"actual":2,"check":"cache-age-oldest-fragment fixture 1","expected":3,"passed":false},{"actual":1,"check":"cache-age-oldest-fragment fixture 2","expected":1,"passed":true},{"actual":1,"check":"cache-age-oldest-fragment fixture 3","expected":1,"passed":true},{"actual":2,"check":"cache-age-oldest-fragment fixture 4","expected":2,"passed":true},{"actual":0,"check":"cache-age-oldest-fragment fixture 5","expected":1,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"cache-age-oldest-fragment fixture 0\", \"actual\": 3, \"expected\": 4, \"passed\": false}, {\"check\": \"cache-age-oldest-fragment fixture 1\", \"actual\": 2, \"expected\": 3, \"passed\": false}, {\"check\": \"cache-age-oldest-fragment fixture 2\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 3\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 4\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 5\", \"actual\": 0, \"expected\": 1, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.087,"exit_code":1,"observations":[{"actual":2,"check":"cache-age-oldest-fragment fixture 0","expected":4,"passed":false},{"actual":1,"check":"cache-age-oldest-fragment fixture 1","expected":3,"passed":false},{"actual":1,"check":"cache-age-oldest-fragment fixture 2","expected":1,"passed":true},{"actual":1,"check":"cache-age-oldest-fragment fixture 3","expected":1,"passed":true},{"actual":2,"check":"cache-age-oldest-fragment fixture 4","expected":2,"passed":true},{"actual":0,"check":"cache-age-oldest-fragment fixture 5","expected":1,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"cache-age-oldest-fragment fixture 0\", \"actual\": 2, \"expected\": 4, \"passed\": false}, {\"check\": \"cache-age-oldest-fragment fixture 1\", \"actual\": 1, \"expected\": 3, \"passed\": false}, {\"check\": \"cache-age-oldest-fragment fixture 2\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 3\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 4\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 5\", \"actual\": 0, \"expected\": 1, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.669,"exit_code":0,"observations":[{"actual":4,"check":"cache-age-oldest-fragment fixture 0","expected":4,"passed":true},{"actual":3,"check":"cache-age-oldest-fragment fixture 1","expected":3,"passed":true},{"actual":1,"check":"cache-age-oldest-fragment fixture 2","expected":1,"passed":true},{"actual":1,"check":"cache-age-oldest-fragment fixture 3","expected":1,"passed":true},{"actual":2,"check":"cache-age-oldest-fragment fixture 4","expected":2,"passed":true},{"actual":1,"check":"cache-age-oldest-fragment fixture 5","expected":1,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"cache-age-oldest-fragment fixture 0\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 1\", \"actual\": 3, \"expected\": 3, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 2\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 3\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 4\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"cache-age-oldest-fragment fixture 5\", \"actual\": 1, \"expected\": 1, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}