{"abstract":"String precision pads rather than truncates.","category":"Serialization","checks":4,"contract":"Format text to at most three codepoints without width padding.","evaluation_group":"model-bb8c1077b414cc45","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-format-string-precision","id":"FA-3831","implementations":{"attempt":{"sha256":"836b4692b96f28ddd53fed37bf22d947f0d67a5d697430ad1985262f6b6f361f","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[:3].ljust(3)\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('abcdef'), 'abc')\ncheck('boundary 2', solve('a'), 'a')\ncheck('boundary 3', solve('😀abx'), '😀ab')\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":"7670432302f97c9340651b5450eadeb144c0ee3e345868a5777631479eca7abd","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(3)\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('abcdef'), 'abc')\ncheck('boundary 2', solve('a'), 'a')\ncheck('boundary 3', solve('😀abx'), '😀ab')\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":"ccea1b84bae1ae10d5e2f32c9a0772476d0b264bccfeb8fb5c6a0b7753d80cd4","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 '{:.3}'.format(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('abcdef'), 'abc')\ncheck('boundary 2', solve('a'), 'a')\ncheck('boundary 3', solve('😀abx'), '😀ab')\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-format-string-precision","generated_at":"2026-09-29T14:37:31.435984+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: Format text to at most three codepoints without width padding.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Format text to at most three codepoints without width padding.","sha256":"3eaec1af355cb8e39a2c387e1fc99a7a504b70bdcb55b6a2910ed53254befbd3","title":"String precision pads rather than truncates · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":56.168,"exit_code":1,"observations":[{"actual":"abc","check":"boundary 1","expected":"abc","passed":true},{"actual":"a  ","check":"boundary 2","expected":"a","passed":false},{"actual":"😀ab","check":"boundary 3","expected":"😀ab","passed":true},{"actual":"   ","check":"boundary 4","expected":"","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"abc\", \"expected\": \"abc\", \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": \"a  \", \"expected\": \"a\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"😀ab\", \"expected\": \"😀ab\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"   \", \"expected\": \"\", \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":52.968,"exit_code":1,"observations":[{"actual":"abcdef","check":"boundary 1","expected":"abc","passed":false},{"actual":"a  ","check":"boundary 2","expected":"a","passed":false},{"actual":"😀abx","check":"boundary 3","expected":"😀ab","passed":false},{"actual":"   ","check":"boundary 4","expected":"","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"abcdef\", \"expected\": \"abc\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"a  \", \"expected\": \"a\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"😀abx\", \"expected\": \"😀ab\", \"passed\": false}, {\"check\": \"boundary 4\", \"actual\": \"   \", \"expected\": \"\", \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":54.77,"exit_code":0,"observations":[{"actual":"abc","check":"boundary 1","expected":"abc","passed":true},{"actual":"a","check":"boundary 2","expected":"a","passed":true},{"actual":"😀ab","check":"boundary 3","expected":"😀ab","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\": \"a\", \"expected\": \"a\", \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": \"😀ab\", \"expected\": \"😀ab\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}