{"abstract":"Odd center padding goes to the wrong side.","category":"Text processing","checks":4,"contract":"Center a string to width six using periods and Python centering allocation.","evaluation_group":"model-fe7972b4c0b6ea86","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-center-odd-padding","id":"FA-3046","implementations":{"attempt":{"sha256":"a45874f81cb4caa010816659b635ca4c9314dbf234d6922b85f9e1f355f73dc1","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 '.'*((6-len(x)+1)//2)+x+'.'*max(0,(6-len(x))//2)\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('abc'), '.abc..')\ncheck('boundary 2', solve('ab'), '..ab..')\ncheck('boundary 3', solve('abcdefg'), 'abcdefg')\ncheck('boundary 4', solve(''), '......')\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":"964f5802e8888209fc20837b3332a8bb15432e17210575c59bab771790000b47","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 x.ljust(6,'.')\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('abc'), '.abc..')\ncheck('boundary 2', solve('ab'), '..ab..')\ncheck('boundary 3', solve('abcdefg'), 'abcdefg')\ncheck('boundary 4', solve(''), '......')\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":"c1589c49936bb7c17f8f17ad2cdd7291f64d50881341bac0a0ae092e00a15330","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 x.center(6,'.')\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('abc'), '.abc..')\ncheck('boundary 2', solve('ab'), '..ab..')\ncheck('boundary 3', solve('abcdefg'), 'abcdefg')\ncheck('boundary 4', solve(''), '......')\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-center-odd-padding","generated_at":"2026-09-29T14:37:20.759320+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: Center a string to width six using periods and Python centering allocation.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Center a string to width six using periods and Python centering allocation.","sha256":"bb2f2d373d550e4e8a05f03473004922c89760f4ba9ab3e8296eb49715535248","title":"Odd center padding goes to the wrong side · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":61.86,"exit_code":1,"observations":[{"actual":"..abc.","check":"boundary 1","expected":".abc..","passed":false},{"actual":"..ab..","check":"boundary 2","expected":"..ab..","passed":true},{"actual":"abcdefg","check":"boundary 3","expected":"abcdefg","passed":true},{"actual":"......","check":"boundary 4","expected":"......","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"..abc.\", \"expected\": \".abc..\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"..ab..\", \"expected\": \"..ab..\", \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": \"abcdefg\", \"expected\": \"abcdefg\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"......\", \"expected\": \"......\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":57.629,"exit_code":1,"observations":[{"actual":"abc...","check":"boundary 1","expected":".abc..","passed":false},{"actual":"ab....","check":"boundary 2","expected":"..ab..","passed":false},{"actual":"abcdefg","check":"boundary 3","expected":"abcdefg","passed":true},{"actual":"......","check":"boundary 4","expected":"......","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"abc...\", \"expected\": \".abc..\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"ab....\", \"expected\": \"..ab..\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"abcdefg\", \"expected\": \"abcdefg\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"......\", \"expected\": \"......\", \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":57.927,"exit_code":0,"observations":[{"actual":".abc..","check":"boundary 1","expected":".abc..","passed":true},{"actual":"..ab..","check":"boundary 2","expected":"..ab..","passed":true},{"actual":"abcdefg","check":"boundary 3","expected":"abcdefg","passed":true},{"actual":"......","check":"boundary 4","expected":"......","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \".abc..\", \"expected\": \".abc..\", \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": \"..ab..\", \"expected\": \"..ab..\", \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": \"abcdefg\", \"expected\": \"abcdefg\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"......\", \"expected\": \"......\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}