{"abstract":"Explicit empty defaults are ignored.","category":"Configuration","checks":8,"contract":"For declared variable names return exact present environment value, otherwise explicit default including empty values. Required missing values report missing; optional missing values are omitted. Prefix is prepended before lookup.","evaluation_group":"xt-env-projection","failed_approach":"The attempted repair substitutes elif default not in (None, ''):. Fixture 4 still yields {'PORT': 'missing'} instead of {'PORT': ''}.","family":"xt-env-projection-empty-default","id":"FA-9641","implementations":{"attempt":{"sha256":"f2f8be44577f9a12c08bcac8b37481aa99cc29583d627b1a7fd7becd5f7b33b9","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(declarations, environment, prefix):\n    result = {}\n    for name, default, required in declarations:\n        key = prefix + name\n        if key in environment: result[name] = environment[key]\n        elif default not in (None, ''): result[name] = default\n        elif required: result[name] = 'missing'\n    return result\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve([], {}, 'APP_'), {})\ncheck('fixture 2', solve([('PORT', None, True)], {'APP_PORT': '0'}, 'APP_'), {'PORT': '0'})\ncheck('fixture 3', solve([('PORT', '80', True)], {'APP_PORT': ''}, 'APP_'), {'PORT': ''})\ncheck('fixture 4', solve([('PORT', '', True)], {}, 'APP_'), {'PORT': ''})\ncheck('fixture 5', solve([('PORT', None, True)], {}, 'APP_'), {'PORT': 'missing'})\ncheck('fixture 6', solve([('PORT', None, False)], {}, 'APP_'), {})\ncheck('fixture 7', solve([('PORT', '80', False)], {}, 'APP_'), {'PORT': '80'})\ncheck('fixture 8', solve([('PORT', '80', True)], {'PORT': '90'}, 'APP_'), {'PORT': '80'})\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":"46d1364707a9f7ec41f1d58b61c82cf8bd54bbe99249e5d994935b097649858e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(declarations, environment, prefix):\n    result = {}\n    for name, default, required in declarations:\n        key = prefix + name\n        if key in environment: result[name] = environment[key]\n        elif default: result[name] = default\n        elif required: result[name] = 'missing'\n    return result\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve([], {}, 'APP_'), {})\ncheck('fixture 2', solve([('PORT', None, True)], {'APP_PORT': '0'}, 'APP_'), {'PORT': '0'})\ncheck('fixture 3', solve([('PORT', '80', True)], {'APP_PORT': ''}, 'APP_'), {'PORT': ''})\ncheck('fixture 4', solve([('PORT', '', True)], {}, 'APP_'), {'PORT': ''})\ncheck('fixture 5', solve([('PORT', None, True)], {}, 'APP_'), {'PORT': 'missing'})\ncheck('fixture 6', solve([('PORT', None, False)], {}, 'APP_'), {})\ncheck('fixture 7', solve([('PORT', '80', False)], {}, 'APP_'), {'PORT': '80'})\ncheck('fixture 8', solve([('PORT', '80', True)], {'PORT': '90'}, 'APP_'), {'PORT': '80'})\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":"49862693840bf82a6bde42dcd4a36b72a4730be0c206287b424f5c752a899d5e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(declarations, environment, prefix):\n    result = {}\n    for name, default, required in declarations:\n        key = prefix + name\n        if key in environment: result[name] = environment[key]\n        elif default is not None: result[name] = default\n        elif required: result[name] = 'missing'\n    return result\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve([], {}, 'APP_'), {})\ncheck('fixture 2', solve([('PORT', None, True)], {'APP_PORT': '0'}, 'APP_'), {'PORT': '0'})\ncheck('fixture 3', solve([('PORT', '80', True)], {'APP_PORT': ''}, 'APP_'), {'PORT': ''})\ncheck('fixture 4', solve([('PORT', '', True)], {}, 'APP_'), {'PORT': ''})\ncheck('fixture 5', solve([('PORT', None, True)], {}, 'APP_'), {'PORT': 'missing'})\ncheck('fixture 6', solve([('PORT', None, False)], {}, 'APP_'), {})\ncheck('fixture 7', solve([('PORT', '80', False)], {}, 'APP_'), {'PORT': '80'})\ncheck('fixture 8', solve([('PORT', '80', True)], {'PORT': '90'}, 'APP_'), {'PORT': '80'})\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":"xt-env-projection-empty-default","generated_at":"2026-09-29T14:38:31.656270+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"An offline model of environment variable projection, suitable for testing build and release tooling without external services.","repair":"Treat every non-None default as present.","root_cause":"The implementation substitutes elif default: for elif default is not None:, so explicit empty defaults are ignored.","sha256":"5f52e894745f04834c1a6565b073fc9bed95044d041d6120fce148e3ca03b76a","title":"Environment variable projection: Explicit empty defaults are ignored · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.817,"exit_code":1,"observations":[{"actual":{},"check":"fixture 1","expected":{},"passed":true},{"actual":{"PORT":"0"},"check":"fixture 2","expected":{"PORT":"0"},"passed":true},{"actual":{"PORT":""},"check":"fixture 3","expected":{"PORT":""},"passed":true},{"actual":{"PORT":"missing"},"check":"fixture 4","expected":{"PORT":""},"passed":false},{"actual":{"PORT":"missing"},"check":"fixture 5","expected":{"PORT":"missing"},"passed":true},{"actual":{},"check":"fixture 6","expected":{},"passed":true},{"actual":{"PORT":"80"},"check":"fixture 7","expected":{"PORT":"80"},"passed":true},{"actual":{"PORT":"80"},"check":"fixture 8","expected":{"PORT":"80"},"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": {\"PORT\": \"0\"}, \"expected\": {\"PORT\": \"0\"}, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": {\"PORT\": \"\"}, \"expected\": {\"PORT\": \"\"}, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": {\"PORT\": \"missing\"}, \"expected\": {\"PORT\": \"\"}, \"passed\": false}, {\"check\": \"fixture 5\", \"actual\": {\"PORT\": \"missing\"}, \"expected\": {\"PORT\": \"missing\"}, \"passed\": true}, {\"check\": \"fixture 6\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"fixture 7\", \"actual\": {\"PORT\": \"80\"}, \"expected\": {\"PORT\": \"80\"}, \"passed\": true}, {\"check\": \"fixture 8\", \"actual\": {\"PORT\": \"80\"}, \"expected\": {\"PORT\": \"80\"}, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":37.155,"exit_code":1,"observations":[{"actual":{},"check":"fixture 1","expected":{},"passed":true},{"actual":{"PORT":"0"},"check":"fixture 2","expected":{"PORT":"0"},"passed":true},{"actual":{"PORT":""},"check":"fixture 3","expected":{"PORT":""},"passed":true},{"actual":{"PORT":"missing"},"check":"fixture 4","expected":{"PORT":""},"passed":false},{"actual":{"PORT":"missing"},"check":"fixture 5","expected":{"PORT":"missing"},"passed":true},{"actual":{},"check":"fixture 6","expected":{},"passed":true},{"actual":{"PORT":"80"},"check":"fixture 7","expected":{"PORT":"80"},"passed":true},{"actual":{"PORT":"80"},"check":"fixture 8","expected":{"PORT":"80"},"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": {\"PORT\": \"0\"}, \"expected\": {\"PORT\": \"0\"}, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": {\"PORT\": \"\"}, \"expected\": {\"PORT\": \"\"}, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": {\"PORT\": \"missing\"}, \"expected\": {\"PORT\": \"\"}, \"passed\": false}, {\"check\": \"fixture 5\", \"actual\": {\"PORT\": \"missing\"}, \"expected\": {\"PORT\": \"missing\"}, \"passed\": true}, {\"check\": \"fixture 6\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"fixture 7\", \"actual\": {\"PORT\": \"80\"}, \"expected\": {\"PORT\": \"80\"}, \"passed\": true}, {\"check\": \"fixture 8\", \"actual\": {\"PORT\": \"80\"}, \"expected\": {\"PORT\": \"80\"}, \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":39.264,"exit_code":0,"observations":[{"actual":{},"check":"fixture 1","expected":{},"passed":true},{"actual":{"PORT":"0"},"check":"fixture 2","expected":{"PORT":"0"},"passed":true},{"actual":{"PORT":""},"check":"fixture 3","expected":{"PORT":""},"passed":true},{"actual":{"PORT":""},"check":"fixture 4","expected":{"PORT":""},"passed":true},{"actual":{"PORT":"missing"},"check":"fixture 5","expected":{"PORT":"missing"},"passed":true},{"actual":{},"check":"fixture 6","expected":{},"passed":true},{"actual":{"PORT":"80"},"check":"fixture 7","expected":{"PORT":"80"},"passed":true},{"actual":{"PORT":"80"},"check":"fixture 8","expected":{"PORT":"80"},"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": {\"PORT\": \"0\"}, \"expected\": {\"PORT\": \"0\"}, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": {\"PORT\": \"\"}, \"expected\": {\"PORT\": \"\"}, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": {\"PORT\": \"\"}, \"expected\": {\"PORT\": \"\"}, \"passed\": true}, {\"check\": \"fixture 5\", \"actual\": {\"PORT\": \"missing\"}, \"expected\": {\"PORT\": \"missing\"}, \"passed\": true}, {\"check\": \"fixture 6\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"fixture 7\", \"actual\": {\"PORT\": \"80\"}, \"expected\": {\"PORT\": \"80\"}, \"passed\": true}, {\"check\": \"fixture 8\", \"actual\": {\"PORT\": \"80\"}, \"expected\": {\"PORT\": \"80\"}, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}