{"abstract":"Overflow CSV columns overwrite the final header.","category":"Delimited text","checks":4,"contract":"Read two-column a,b CSV as a dictionary, storing overflow cells under extra and missing b as None.","contract_signature":"x","evaluation_group":"model-fecdfdcc08ea22ea","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-csv-dict-extra-columns","id":"FA-3201","implementations":{"attempt":{"sha256":"0c45c6462c1d38156262ca85606422f6d373b30508b8742952f1ec1e3cd2ac57","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 dict(zip(['a','b'],next(csv.reader([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('1,2,3'), {'a': '1', 'b': '2', 'extra': ['3']})\ncheck('boundary 2', solve('1'), {'a': '1', 'b': None})\ncheck('boundary 3', solve('1,'), {'a': '1', 'b': ''})\ncheck('boundary 4', solve('1,2'), {'a': '1', 'b': '2'})\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":"553b117d6ae8aacb1bd0ac072cc071908664fca1f421889f63dfcd88a9e5f1b4","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 dict(zip(['a','b'],next(csv.reader([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('1,2,3'), {'a': '1', 'b': '2', 'extra': ['3']})\ncheck('boundary 2', solve('1'), {'a': '1', 'b': None})\ncheck('boundary 3', solve('1,'), {'a': '1', 'b': ''})\ncheck('boundary 4', solve('1,2'), {'a': '1', 'b': '2'})\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-csv-dict-extra-columns","generated_at":"2026-09-29T14:37:22.552468+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: Read two-column a,b CSV as a dictionary, storing overflow cells under extra and missing b as None.","sha256":"ab07c1f01c707a4441d14284a2a603a80fe69e2e38cee2f97d264a59956cc92e","title":"Overflow CSV columns overwrite the final header · 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":53.026,"exit_code":1,"observations":[{"actual":{"a":"1","b":"2"},"check":"boundary 1","expected":{"a":"1","b":"2","extra":["3"]},"passed":false},{"actual":{"a":"1","b":""},"check":"boundary 2","expected":{"a":"1","b":null},"passed":false},{"actual":{"a":"1","b":""},"check":"boundary 3","expected":{"a":"1","b":""},"passed":true},{"actual":{"a":"1","b":"2"},"check":"boundary 4","expected":{"a":"1","b":"2"},"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": {\"a\": \"1\", \"b\": \"2\"}, \"expected\": {\"a\": \"1\", \"b\": \"2\", \"extra\": [\"3\"]}, \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": {\"a\": \"1\", \"b\": \"\"}, \"expected\": {\"a\": \"1\", \"b\": null}, \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": {\"a\": \"1\", \"b\": \"\"}, \"expected\": {\"a\": \"1\", \"b\": \"\"}, \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": {\"a\": \"1\", \"b\": \"2\"}, \"expected\": {\"a\": \"1\", \"b\": \"2\"}, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":54.761,"exit_code":1,"observations":[{"actual":{"a":"1","b":"2"},"check":"boundary 1","expected":{"a":"1","b":"2","extra":["3"]},"passed":false},{"actual":{"a":"1"},"check":"boundary 2","expected":{"a":"1","b":null},"passed":false},{"actual":{"a":"1","b":""},"check":"boundary 3","expected":{"a":"1","b":""},"passed":true},{"actual":{"a":"1","b":"2"},"check":"boundary 4","expected":{"a":"1","b":"2"},"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": {\"a\": \"1\", \"b\": \"2\"}, \"expected\": {\"a\": \"1\", \"b\": \"2\", \"extra\": [\"3\"]}, \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": {\"a\": \"1\"}, \"expected\": {\"a\": \"1\", \"b\": null}, \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": {\"a\": \"1\", \"b\": \"\"}, \"expected\": {\"a\": \"1\", \"b\": \"\"}, \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": {\"a\": \"1\", \"b\": \"2\"}, \"expected\": {\"a\": \"1\", \"b\": \"2\"}, \"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."}}