{"abstract":"Removing a record terminator erases empty trailing records.","category":"Text processing","checks":4,"contract":"Remove at most one terminal CRLF or LF; preserve lone CR and prior terminators.","evaluation_group":"model-f51db87d08fd0d56","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-trim-one-newline","id":"FA-3871","implementations":{"attempt":{"sha256":"a2cd245b9a47e6295d4f1d82c28b8a8ab3f5d891e1d07bc190c0a85cabfe376f","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[:-1] if x.endswith(('\\r','\\n')) else 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('a\\n\\n'), 'a\\n')\ncheck('boundary 2', solve('a\\r\\n'), 'a')\ncheck('boundary 3', solve('a\\r'), 'a\\r')\ncheck('boundary 4', solve('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":"d5a78416955c65eb6b09708fde27a8cd51012fac390e6dc3f3f719d6846d8d5a","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.rstrip('\\r\\n')\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('a\\n\\n'), 'a\\n')\ncheck('boundary 2', solve('a\\r\\n'), 'a')\ncheck('boundary 3', solve('a\\r'), 'a\\r')\ncheck('boundary 4', solve('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"},"fixed":{"sha256":"f1be4f80a83c560fc1105229a8ce8ae8ddcea913187da7341943df919f18ae28","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[:-2] if x.endswith('\\r\\n') else x[:-1] if x.endswith('\\n') else 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('a\\n\\n'), 'a\\n')\ncheck('boundary 2', solve('a\\r\\n'), 'a')\ncheck('boundary 3', solve('a\\r'), 'a\\r')\ncheck('boundary 4', solve('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":"xp-trim-one-newline","generated_at":"2026-09-29T14:37:32.190899+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: Remove at most one terminal CRLF or LF; preserve lone CR and prior terminators.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Remove at most one terminal CRLF or LF; preserve lone CR and prior terminators.","sha256":"c42f157c6877a663ba1715e94107c1ae1b62dde569791924966ec9b1810fcf2f","title":"Removing a record terminator erases empty trailing records · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":57.461,"exit_code":1,"observations":[{"actual":"a\n","check":"boundary 1","expected":"a\n","passed":true},{"actual":"a\r","check":"boundary 2","expected":"a","passed":false},{"actual":"a","check":"boundary 3","expected":"a\r","passed":false},{"actual":"a","check":"boundary 4","expected":"a","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"a\\n\", \"expected\": \"a\\n\", \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": \"a\\r\", \"expected\": \"a\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"a\", \"expected\": \"a\\r\", \"passed\": false}, {\"check\": \"boundary 4\", \"actual\": \"a\", \"expected\": \"a\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":58.619,"exit_code":1,"observations":[{"actual":"a","check":"boundary 1","expected":"a\n","passed":false},{"actual":"a","check":"boundary 2","expected":"a","passed":true},{"actual":"a","check":"boundary 3","expected":"a\r","passed":false},{"actual":"a","check":"boundary 4","expected":"a","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"a\", \"expected\": \"a\\n\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"a\", \"expected\": \"a\", \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": \"a\", \"expected\": \"a\\r\", \"passed\": false}, {\"check\": \"boundary 4\", \"actual\": \"a\", \"expected\": \"a\", \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":157.64,"exit_code":0,"observations":[{"actual":"a\n","check":"boundary 1","expected":"a\n","passed":true},{"actual":"a","check":"boundary 2","expected":"a","passed":true},{"actual":"a\r","check":"boundary 3","expected":"a\r","passed":true},{"actual":"a","check":"boundary 4","expected":"a","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"a\\n\", \"expected\": \"a\\n\", \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": \"a\", \"expected\": \"a\", \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": \"a\\r\", \"expected\": \"a\\r\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"a\", \"expected\": \"a\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}