pkg-be-plugin is a pkg(8) plugin that automatically creates a ZFS
boot environment before each install, upgrade, or deinstall
transaction. If a transaction leaves the system in a broken state,
the pre-transaction BE provides a clean rollback point.

The plugin uses libbe(3) directly with no subprocess invocations of
bectl(8) or zfs(8). Boot environments are pruned automatically based
on a configurable keep count and minimum age.