This gap was hiding a catastrophe. TrueNAS 26 deletes plugins/zfs_/dataset.py and plugins/zfs_/snapshot.py outright, taking zfs.dataset.query, zfs.snapshot.query and zfs.snapshot.delete with them (26 uses filesystem.statfs and zfs.resource.*). Nothing about the five cloud_backup files reveals that, so every other check went green -- including the one I had just added. The patch would have applied cleanly and then failed on the first backup, or worse: snapshotted fine and failed to DELETE, orphaning one snapshot per descendant dataset (250 on a real pool) on every run, forever. So 26 is BROKEN and the nested module will not apply there. The async/sync wrapper work and the vendored get_dataset_recursive stay -- they are correct and necessary -- but 26 is not supported until the ZFS calls are ported, and that needs a real 26 box to verify. Shipping a port nobody has run is the failure this project exists to avoid. Also: do_delete is recognised as delete (24.10/25.04 use the CRUDService convention), which was reporting both as BROKEN -- a false verdict that would have disabled nested snapshots on boxes where they work.