{"abstract":"Required absent variables are silently omitted.","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.","contract_signature":"declarations, environment, prefix","evaluation_group":"xt-env-projection","failed_approach":"The attempted repair substitutes elif required: result[name] = None. Fixture 5 still yields {'PORT': None} instead of {'PORT': 'missing'}.","family":"xt-env-projection-required-missing","id":"FA-9646","implementations":{"attempt":{"sha256":"b6d5968801be435c99e08c3d18f809483f30a6291af65bc18816e51be76c53de","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] = None\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":"fb794a7702bf0f38652c11996ea54153d0df9bc8e16968c9a145fdf613c3bdf3","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: pass\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-required-missing","generated_at":"2026-09-29T14:38:31.771218+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.","root_cause":"The implementation substitutes elif required: pass for elif required: result[name] = 'missing', so required absent variables are silently omitted.","sha256":"d6cdc5f3dc295e287345dc589a57d81249c3527819ec1620370cb799caaa13e1","title":"Environment variable projection: Required absent variables are silently omitted · 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":38.595,"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":""},"check":"fixture 4","expected":{"PORT":""},"passed":true},{"actual":{"PORT":null},"check":"fixture 5","expected":{"PORT":"missing"},"passed":false},{"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\": \"\"}, \"expected\": {\"PORT\": \"\"}, \"passed\": true}, {\"check\": \"fixture 5\", \"actual\": {\"PORT\": null}, \"expected\": {\"PORT\": \"missing\"}, \"passed\": false}, {\"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":38.452,"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":""},"check":"fixture 4","expected":{"PORT":""},"passed":true},{"actual":{},"check":"fixture 5","expected":{"PORT":"missing"},"passed":false},{"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\": \"\"}, \"expected\": {\"PORT\": \"\"}, \"passed\": true}, {\"check\": \"fixture 5\", \"actual\": {}, \"expected\": {\"PORT\": \"missing\"}, \"passed\": false}, {\"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"}},"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."}}