can not disable zfs snapshot/pool/filesystem scanning in grub

[pseudoterminal X0]

I've currently got an issue where encrypted backups on an external pool whose key are unavailable are being scanned during `grub-mkconfig`, causing it to error out during `zfs_mount_at()` because the key is unavailable.

I've traced it down to the /etc/grub.d/10_linux_zfs support file which scans pools and filesystems indiscriminately, no options to configure in /etc/default/grub or /etc/default/zfs.

Although, /etc/default/zfs has the `ZPOOL_IMPORT_ALL_VISIBLE='no'` that I have set explicitly, and it is ignored during grub-mkconfig only. Even if my zpool isn't imported, it's scanned (I hear the HDD spin up) and erroneously included.

Package: grub-common
Status: install ok installed
Priority: optional
Section: admin
Installed-Size: 13836
Maintainer: Ubuntu Developers <email address hidden>
Architecture: amd64
Multi-Arch: foreign
Source: grub2
Version: 2.06-2ubuntu6

[pseudoterminal X0 (ptx0)]

this is particularly troublesome, can we get some kind of update?