{"abstract":"A suffix comparison scans from the front.","category":"Text processing","checks":4,"contract":"Find the longest character suffix shared by all inputs; empty input gives empty string.","contract_signature":"x","evaluation_group":"model-cab736309e53f42d","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-common-suffix-direction","id":"FA-3951","implementations":{"attempt":{"sha256":"66413b05c413e7afd974e5715e2951896e72b97dad5bcff5f418ecce65098f28","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[0] if x and all(v.endswith(x[0]) for v in x) else ''\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(['walking', 'talking']), 'alking')\ncheck('boundary 2', solve(['a.txt', 'b.txt']), '.txt')\ncheck('boundary 3', solve([]), '')\ncheck('boundary 4', solve(['x', 'abx']), 'x')\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":"857a153e798c2292cf20b01895c3cd1e3bd7e76189256cc24fa61fc2462fcebe","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 min(x,key=len) if x else ''\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(['walking', 'talking']), 'alking')\ncheck('boundary 2', solve(['a.txt', 'b.txt']), '.txt')\ncheck('boundary 3', solve([]), '')\ncheck('boundary 4', solve(['x', 'abx']), 'x')\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-common-suffix-direction","generated_at":"2026-09-29T14:37:33.506620+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.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Find the longest character suffix shared by all inputs; empty input gives empty string.","sha256":"9ea7c5f337ced79db4c54f7d63a797e0cec3c225326cb951a2c9e215710f99b5","title":"A suffix comparison scans from the front · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":63.076,"exit_code":1,"observations":[{"actual":"","check":"boundary 1","expected":"alking","passed":false},{"actual":"","check":"boundary 2","expected":".txt","passed":false},{"actual":"","check":"boundary 3","expected":"","passed":true},{"actual":"x","check":"boundary 4","expected":"x","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"\", \"expected\": \"alking\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"\", \"expected\": \".txt\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"x\", \"expected\": \"x\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":59.245,"exit_code":1,"observations":[{"actual":"walking","check":"boundary 1","expected":"alking","passed":false},{"actual":"a.txt","check":"boundary 2","expected":".txt","passed":false},{"actual":"","check":"boundary 3","expected":"","passed":true},{"actual":"x","check":"boundary 4","expected":"x","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"walking\", \"expected\": \"alking\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"a.txt\", \"expected\": \".txt\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"x\", \"expected\": \"x\", \"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."}}