{"abstract":"The operation returns a result or retained state that violates this contract: Group consecutive equal values into [key,group] pairs; separated equal runs remain separate.","category":"Iterator consumption","checks":4,"contract":"Group consecutive equal values into [key,group] pairs; separated equal runs remain separate. Inputs are the finite Python values shown by the executable fixtures; no concurrent execution is assumed.","contract_signature":"x, y=None","evaluation_group":"model-76abd571aefd3eda","failed_approach":"Sorting first changes run order and merges separated runs.","family":"xr-groupby-adjacency-not-global-key","id":"FA-4566","implementations":{"attempt":{"sha256":"2600f5018aeb9d7ee35e466d9eb69c2fe013789ead8a71e8de0d4c3d06939a77","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 [[k,list(g)] for k,g in it.groupby(sorted(x))]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('separate equal runs', solve(['a', 'b', 'a']), [['a', ['a']], ['b', ['b']], ['a', ['a']]])\ncheck('same run', solve(['a', 'a']), [['a', ['a', 'a']]])\ncheck('empty', solve([]), [])\ncheck('nonlexical runs', solve(['b', 'b', 'a']), [['b', ['b', 'b']], ['a', ['a']]])\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":"e3f594f64e5e2768af81025c2deb675c3ff96ac1243249e3cb3ef7814e478a35","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 [[k,[v for v in x if v==k]] for k in dict.fromkeys(x)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('separate equal runs', solve(['a', 'b', 'a']), [['a', ['a']], ['b', ['b']], ['a', ['a']]])\ncheck('same run', solve(['a', 'a']), [['a', ['a', 'a']]])\ncheck('empty', solve([]), [])\ncheck('nonlexical runs', solve(['b', 'b', 'a']), [['b', ['b', 'b']], ['a', ['a']]])\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-groupby-adjacency-not-global-key","generated_at":"2026-09-29T14:37:40.569835+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":"Global key grouping merges separate adjacent runs with the same key.","sha256":"73454cce7560ecf94875845f23f4c75893112dea0152ef130a660387e8735bce","title":"Groupby adjacency not global key · 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":39.299,"exit_code":1,"observations":[{"actual":[["a",["a","a"]],["b",["b"]]],"check":"separate equal runs","expected":[["a",["a"]],["b",["b"]],["a",["a"]]],"passed":false},{"actual":[["a",["a","a"]]],"check":"same run","expected":[["a",["a","a"]]],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[["a",["a"]],["b",["b","b"]]],"check":"nonlexical runs","expected":[["b",["b","b"]],["a",["a"]]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"separate equal runs\", \"actual\": [[\"a\", [\"a\", \"a\"]], [\"b\", [\"b\"]]], \"expected\": [[\"a\", [\"a\"]], [\"b\", [\"b\"]], [\"a\", [\"a\"]]], \"passed\": false}, {\"check\": \"same run\", \"actual\": [[\"a\", [\"a\", \"a\"]]], \"expected\": [[\"a\", [\"a\", \"a\"]]], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"nonlexical runs\", \"actual\": [[\"a\", [\"a\"]], [\"b\", [\"b\", \"b\"]]], \"expected\": [[\"b\", [\"b\", \"b\"]], [\"a\", [\"a\"]]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.225,"exit_code":1,"observations":[{"actual":[["a",["a","a"]],["b",["b"]]],"check":"separate equal runs","expected":[["a",["a"]],["b",["b"]],["a",["a"]]],"passed":false},{"actual":[["a",["a","a"]]],"check":"same run","expected":[["a",["a","a"]]],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[["b",["b","b"]],["a",["a"]]],"check":"nonlexical runs","expected":[["b",["b","b"]],["a",["a"]]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"separate equal runs\", \"actual\": [[\"a\", [\"a\", \"a\"]], [\"b\", [\"b\"]]], \"expected\": [[\"a\", [\"a\"]], [\"b\", [\"b\"]], [\"a\", [\"a\"]]], \"passed\": false}, {\"check\": \"same run\", \"actual\": [[\"a\", [\"a\", \"a\"]]], \"expected\": [[\"a\", [\"a\", \"a\"]]], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"nonlexical runs\", \"actual\": [[\"b\", [\"b\", \"b\"]], [\"a\", [\"a\"]]], \"expected\": [[\"b\", [\"b\", \"b\"]], [\"a\", [\"a\"]]], \"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."}}