This bug was fixed in the package grub2 - 2.12~rc1-4ubuntu3
--------------- grub2 (2.12~rc1-4ubuntu3) mantic; urgency=medium
* zfs: Drop `set -u`, incompatible with undefined variables in library (LP: #2033256)
-- Julian Andres Klode <email address hidden> Tue, 29 Aug 2023 16:03:49 +0200
This bug was fixed in the package grub2 - 2.12~rc1-4ubuntu3
---------------
grub2 (2.12~rc1-4ubuntu3) mantic; urgency=medium
* zfs: Drop `set -u`, incompatible with undefined variables in library
(LP: #2033256)
-- Julian Andres Klode <email address hidden> Tue, 29 Aug 2023 16:03:49 +0200