{"abstract":"A zero retention count keeps historical releases.","category":"Deployment models","checks":7,"contract":"Retain active and explicitly pinned releases regardless of age, retain newest successful unpinned releases up to limit, exclude unsuccessful unpinned releases, and return sorted unique revision IDs.","contract_signature":"releases, active, pinned, limit","evaluation_group":"xt-release-retention","failed_approach":"The attempted repair substitutes eligible. Fixture 3 still yields [1, 2, 3] instead of [2, 3].","family":"xt-release-retention-limit-retention","id":"FA-10201","implementations":{"attempt":{"sha256":"d9d744188c6f3df6754b2646f8449d69cf88bf6c7c0f6d1e6358d267bf1739e4","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(releases, active, pinned, limit):\n    keep = {active} | set(pinned)\n    eligible = sorted([number for number, success in releases if success and number not in keep], reverse=True)\n    keep.update(eligible)\n    return sorted(keep)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve([], 1, [], 0), [1])\ncheck('fixture 2', solve([], 4, [1, 2], 0), [1, 2, 4])\ncheck('fixture 3', solve([(1, True), (2, True), (3, True)], 3, [], 1), [2, 3])\ncheck('fixture 4', solve([(1, True), (2, False), (3, True)], 3, [], 1), [1, 3])\ncheck('fixture 5', solve([(1, True), (2, True), (3, True)], 3, [1], 0), [1, 3])\ncheck('fixture 6', solve([(1, True), (2, True), (3, True), (4, True)], 4, [2], 1), [2, 3, 4])\ncheck('fixture 7', solve([(1, True), (2, True)], 2, [], 0), [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":"5c04d834481ed42f896b48b422cfbcc589d99a57c674ecd4319b52226dd3a24b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(releases, active, pinned, limit):\n    keep = {active} | set(pinned)\n    eligible = sorted([number for number, success in releases if success and number not in keep], reverse=True)\n    keep.update(eligible[:max(1, limit)])\n    return sorted(keep)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve([], 1, [], 0), [1])\ncheck('fixture 2', solve([], 4, [1, 2], 0), [1, 2, 4])\ncheck('fixture 3', solve([(1, True), (2, True), (3, True)], 3, [], 1), [2, 3])\ncheck('fixture 4', solve([(1, True), (2, False), (3, True)], 3, [], 1), [1, 3])\ncheck('fixture 5', solve([(1, True), (2, True), (3, True)], 3, [1], 0), [1, 3])\ncheck('fixture 6', solve([(1, True), (2, True), (3, True), (4, True)], 4, [2], 1), [2, 3, 4])\ncheck('fixture 7', solve([(1, True), (2, True)], 2, [], 0), [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":"xt-release-retention-limit-retention","generated_at":"2026-09-29T14:38:36.672424+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"An offline model of release retention selection, suitable for testing build and release tooling without external services.","root_cause":"The implementation substitutes eligible[:max(1, limit)] for eligible[:limit], so a zero retention count keeps historical releases.","sha256":"0b4ae25496921f97d42e179fd99e01b36a3cf5abd338859555f83f5e04f9cc5b","title":"Release retention selection: A zero retention count keeps historical releases · 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":40.329,"exit_code":1,"observations":[{"actual":[1],"check":"fixture 1","expected":[1],"passed":true},{"actual":[1,2,4],"check":"fixture 2","expected":[1,2,4],"passed":true},{"actual":[1,2,3],"check":"fixture 3","expected":[2,3],"passed":false},{"actual":[1,3],"check":"fixture 4","expected":[1,3],"passed":true},{"actual":[1,2,3],"check":"fixture 5","expected":[1,3],"passed":false},{"actual":[1,2,3,4],"check":"fixture 6","expected":[2,3,4],"passed":false},{"actual":[1,2],"check":"fixture 7","expected":[2],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [1], \"expected\": [1], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [1, 2, 4], \"expected\": [1, 2, 4], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [1, 2, 3], \"expected\": [2, 3], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [1, 3], \"expected\": [1, 3], \"passed\": true}, {\"check\": \"fixture 5\", \"actual\": [1, 2, 3], \"expected\": [1, 3], \"passed\": false}, {\"check\": \"fixture 6\", \"actual\": [1, 2, 3, 4], \"expected\": [2, 3, 4], \"passed\": false}, {\"check\": \"fixture 7\", \"actual\": [1, 2], \"expected\": [2], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.947,"exit_code":1,"observations":[{"actual":[1],"check":"fixture 1","expected":[1],"passed":true},{"actual":[1,2,4],"check":"fixture 2","expected":[1,2,4],"passed":true},{"actual":[2,3],"check":"fixture 3","expected":[2,3],"passed":true},{"actual":[1,3],"check":"fixture 4","expected":[1,3],"passed":true},{"actual":[1,2,3],"check":"fixture 5","expected":[1,3],"passed":false},{"actual":[2,3,4],"check":"fixture 6","expected":[2,3,4],"passed":true},{"actual":[1,2],"check":"fixture 7","expected":[2],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [1], \"expected\": [1], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [1, 2, 4], \"expected\": [1, 2, 4], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [2, 3], \"expected\": [2, 3], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [1, 3], \"expected\": [1, 3], \"passed\": true}, {\"check\": \"fixture 5\", \"actual\": [1, 2, 3], \"expected\": [1, 3], \"passed\": false}, {\"check\": \"fixture 6\", \"actual\": [2, 3, 4], \"expected\": [2, 3, 4], \"passed\": true}, {\"check\": \"fixture 7\", \"actual\": [1, 2], \"expected\": [2], \"passed\": false}], \"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."}}