Issue description

As @pbogdan found in staging-next:

The xfsprogs update seems to break the LVM installer test. Looks to be an instance of https://bugzilla.redhat.com/show_bug.cgi?id=1575797 that's been patched in grub http://git.savannah.gnu.org/cgit/grub.git/commit/?id=cda0a857dd7a27cd5d621747464bfe71e8727fff.

failure on hydra: https://hydra.nixos.org/build/85713125