{"abstract":"Line deduplication sorts instead of preserving encounter order.","category":"Text processing","checks":4,"contract":"Return first occurrence of each line in encounter order, comparing exact strings.","contract_signature":"x","evaluation_group":"model-86cc6cd89ca4105e","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-deduplicate-lines-stable","id":"FA-3861","implementations":{"attempt":{"sha256":"d51d434246be9500fc9b158485b21ce2436c5b16f49ca5a1e39b0c69c8f80c4f","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 list(dict.fromkeys(v.strip() for v in 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(['b', 'a', 'b']), ['b', 'a'])\ncheck('boundary 2', solve(['a', ' a']), ['a', ' a'])\ncheck('boundary 3', solve([]), [])\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":"f60197c5298b83a40956cad1f0693bd21e452b6904fef975eedfa4ea0609dd1a","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 sorted(set(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(['b', 'a', 'b']), ['b', 'a'])\ncheck('boundary 2', solve(['a', ' a']), ['a', ' a'])\ncheck('boundary 3', solve([]), [])\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-deduplicate-lines-stable","generated_at":"2026-09-29T14:37:32.186748+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: Return first occurrence of each line in encounter order, comparing exact strings.","sha256":"55490b1caee2405f844232eeb671eec836a4420943ac3f3780a8f8e6305c4ed7","title":"Line deduplication sorts instead of preserving encounter order · 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":56.55,"exit_code":1,"observations":[{"actual":["b","a"],"check":"boundary 1","expected":["b","a"],"passed":true},{"actual":["a"],"check":"boundary 2","expected":["a"," a"],"passed":false},{"actual":[],"check":"boundary 3","expected":[],"passed":true},{"actual":[""],"check":"boundary 4","expected":[""],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [\"b\", \"a\"], \"expected\": [\"b\", \"a\"], \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": [\"a\"], \"expected\": [\"a\", \" a\"], \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [\"\"], \"expected\": [\"\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":63.934,"exit_code":1,"observations":[{"actual":["a","b"],"check":"boundary 1","expected":["b","a"],"passed":false},{"actual":[" a","a"],"check":"boundary 2","expected":["a"," a"],"passed":false},{"actual":[],"check":"boundary 3","expected":[],"passed":true},{"actual":[""],"check":"boundary 4","expected":[""],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [\"a\", \"b\"], \"expected\": [\"b\", \"a\"], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [\" a\", \"a\"], \"expected\": [\"a\", \" a\"], \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [\"\"], \"expected\": [\"\"], \"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."}}