{"abstract":"A UUID-shaped identifier accepts misplaced separators.","category":"Lexical grammars","checks":4,"contract":"Accept lowercase hex groups of lengths 8-4-4-4-12.","evaluation_group":"model-5e5a9f3a1341c344","failed_approach":"The candidate grammar '[0-9a-fA-F]{8}(?:-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12}' still disagrees with the explicit boundary fixtures.","family":"xp-uuid-hyphen-groups","id":"FA-3406","implementations":{"attempt":{"sha256":"340330abbd55997a1227e3ea734b2dd7546e407eb5c1498edd15c3728bffd430","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return bool(re.fullmatch('[0-9a-fA-F]{8}(?:-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12}',x))\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve('00000000000000000000000000000000000-'), False)\ncheck('boundary 2', solve('ABCDEF00-0000-0000-0000-000000000000'), False)\ncheck('boundary 3', solve('abcdef00-1234-5678-90ab-cdef01234567'), True)\ncheck('boundary 4', solve('00000000-0000-0000-0000-000000000000'), True)\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":"9bb4ba589900e0795bbf36a7665fc94c96daa256a2155d1790cd2be13ce3a4f2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return bool(re.fullmatch('[0-9a-f-]{36}',x))\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve('00000000000000000000000000000000000-'), False)\ncheck('boundary 2', solve('ABCDEF00-0000-0000-0000-000000000000'), False)\ncheck('boundary 3', solve('abcdef00-1234-5678-90ab-cdef01234567'), True)\ncheck('boundary 4', solve('00000000-0000-0000-0000-000000000000'), True)\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":"45a7059ac16d51b0218d1263e446eba77a12a03f9909c52faa35c6f42f9ba310","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return bool(re.fullmatch('[0-9a-f]{8}(?:-[0-9a-f]{4}){3}-[0-9a-f]{12}',x))\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve('00000000000000000000000000000000000-'), False)\ncheck('boundary 2', solve('ABCDEF00-0000-0000-0000-000000000000'), False)\ncheck('boundary 3', solve('abcdef00-1234-5678-90ab-cdef01234567'), True)\ncheck('boundary 4', solve('00000000-0000-0000-0000-000000000000'), True)\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":"xp-uuid-hyphen-groups","generated_at":"2026-09-29T14:37:25.429370+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A local executable model for consumers of structured text; oracle values are authored literals, not outputs copied from the repaired implementation.","repair":"Implement the complete stated contract, including the boundary fixtures: Accept lowercase hex groups of lengths 8-4-4-4-12.","root_cause":"The recognizer uses '[0-9a-f-]{36}', which admits or omits a token shape forbidden by the stated grammar.","sha256":"b4ab9eed26c204449798a85f4a965597899671a09d4ec4eca08b58132e3a75d0","title":"A UUID-shaped identifier accepts misplaced separators · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":52.213,"exit_code":1,"observations":[{"actual":false,"check":"boundary 1","expected":false,"passed":true},{"actual":true,"check":"boundary 2","expected":false,"passed":false},{"actual":true,"check":"boundary 3","expected":true,"passed":true},{"actual":true,"check":"boundary 4","expected":true,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": true, \"expected\": true, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":57.152,"exit_code":1,"observations":[{"actual":true,"check":"boundary 1","expected":false,"passed":false},{"actual":false,"check":"boundary 2","expected":false,"passed":true},{"actual":true,"check":"boundary 3","expected":true,"passed":true},{"actual":true,"check":"boundary 4","expected":true,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": true, \"expected\": true, \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":56.252,"exit_code":0,"observations":[{"actual":false,"check":"boundary 1","expected":false,"passed":true},{"actual":false,"check":"boundary 2","expected":false,"passed":true},{"actual":true,"check":"boundary 3","expected":true,"passed":true},{"actual":true,"check":"boundary 4","expected":true,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": true, \"expected\": true, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}