{"abstract":"Physical slot order is returned as if it were chronological order.","category":"KV cache position mapping","checks":6,"contract":"Given slot values, oldest_slot, and count, return values for count consecutive occupied slots starting at oldest_slot with wraparound. count is between zero and capacity.","contract_signature":"slots, oldest_slot, count","evaluation_group":"xaud-read-ring-logical-order","failed_approach":"Sorting physical slot numbers preserves a deterministic result but reverses wrapped history.","family":"w3-kv-cache-position-mapping-ring-read-order","id":"FA-98551","implementations":{"attempt":{"sha256":"5c60a7d56fbe770d04eac7fd8ef4b40ae918c33bd8ac41649377bae95b9b6ad8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(slots, oldest_slot, count):\n    return [slots[i] for i in sorted((oldest_slot+j)%len(slots) for j in range(count))]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('wrapped sequence',solve(['a','b','c','d'],3,3),['d','a','b'])\ncheck('unwrapped',solve(['a','b','c'],1,2),['b','c'])\ncheck('all slots',solve([0,1,2,3],2,4),[2,3,0,1])\ncheck('empty read',solve(['x','y'],1,0),[])\ncheck('single slot',solve([N],0,1),[N])\ncheck('wrap twice',solve([4,5,6],2,3),[6,4,5])\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":"bb7c3f9fafb4b3afd3dd4eb6b9631d63bbc33bec80bcf57ee842ff577dd028d2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(slots, oldest_slot, count):\n    return [slots[i] for i in range(count)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('wrapped sequence',solve(['a','b','c','d'],3,3),['d','a','b'])\ncheck('unwrapped',solve(['a','b','c'],1,2),['b','c'])\ncheck('all slots',solve([0,1,2,3],2,4),[2,3,0,1])\ncheck('empty read',solve(['x','y'],1,0),[])\ncheck('single slot',solve([N],0,1),[N])\ncheck('wrap twice',solve([4,5,6],2,3),[6,4,5])\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":"These toy integer maps omit tensor layout, concurrency, device memory, and model-specific cache formats. 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-kv-cache-position-mapping-ring-read-order","generated_at":"2026-09-30T16:48:14.106625+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A small in-memory model makes the cache address contract explicit for a serving component.","root_cause":"The ring start pointer is ignored when reading wrapped contents.","sha256":"0cc5c0eab6d55bbc99a9cfbe1a9cc199651cf3b80550f73e44bbbb4c65760644","title":"Ring slots are read in logical order · 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":27.892,"exit_code":1,"observations":[{"actual":["a","b","d"],"check":"wrapped sequence","expected":["d","a","b"],"passed":false},{"actual":["b","c"],"check":"unwrapped","expected":["b","c"],"passed":true},{"actual":[0,1,2,3],"check":"all slots","expected":[2,3,0,1],"passed":false},{"actual":[],"check":"empty read","expected":[],"passed":true},{"actual":[1],"check":"single slot","expected":[1],"passed":true},{"actual":[4,5,6],"check":"wrap twice","expected":[6,4,5],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"wrapped sequence\", \"actual\": [\"a\", \"b\", \"d\"], \"expected\": [\"d\", \"a\", \"b\"], \"passed\": false}, {\"check\": \"unwrapped\", \"actual\": [\"b\", \"c\"], \"expected\": [\"b\", \"c\"], \"passed\": true}, {\"check\": \"all slots\", \"actual\": [0, 1, 2, 3], \"expected\": [2, 3, 0, 1], \"passed\": false}, {\"check\": \"empty read\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"single slot\", \"actual\": [1], \"expected\": [1], \"passed\": true}, {\"check\": \"wrap twice\", \"actual\": [4, 5, 6], \"expected\": [6, 4, 5], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":27.749,"exit_code":1,"observations":[{"actual":["a","b","c"],"check":"wrapped sequence","expected":["d","a","b"],"passed":false},{"actual":["a","b"],"check":"unwrapped","expected":["b","c"],"passed":false},{"actual":[0,1,2,3],"check":"all slots","expected":[2,3,0,1],"passed":false},{"actual":[],"check":"empty read","expected":[],"passed":true},{"actual":[1],"check":"single slot","expected":[1],"passed":true},{"actual":[4,5,6],"check":"wrap twice","expected":[6,4,5],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"wrapped sequence\", \"actual\": [\"a\", \"b\", \"c\"], \"expected\": [\"d\", \"a\", \"b\"], \"passed\": false}, {\"check\": \"unwrapped\", \"actual\": [\"a\", \"b\"], \"expected\": [\"b\", \"c\"], \"passed\": false}, {\"check\": \"all slots\", \"actual\": [0, 1, 2, 3], \"expected\": [2, 3, 0, 1], \"passed\": false}, {\"check\": \"empty read\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"single slot\", \"actual\": [1], \"expected\": [1], \"passed\": true}, {\"check\": \"wrap twice\", \"actual\": [4, 5, 6], \"expected\": [6, 4, 5], \"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."}}