When grub-probe fails, the current code is to just stuff an empty result
in which causes the user to not knowingly have a system that no longer
boots. grub-probe can fail because the ZFS pool that contains the root
filesystem might have features that GRUB does not yet support which is
a common configuration for people with a rpool and a bpool. This behavior
uses the zdb utility to dump the same value as the filesystem label
would print.
Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
