Two hard failures prevented 41-snapshots-btrfs from generating a
snapshot submenu when the root LUKS header is detached and cryptdevice=
uses a /dev/disk/by-id path:
* grub-probe --target=fs_uuid aborted on detached headers.
* grep-based extraction of UUID from GRUB_CMDLINE_LINUX_DEFAULT failed
when cryptdevice= did not contain “UUID=…”.
This patch:
1. Wraps grub-probe in a try/blkid/lsblk cascade that always returns the
filesystem UUID or prints a clear error.
2. Replaces the fixed “cryptomount -u $(grep …UUID=…)” line with logic
that:
• accepts both UUID=… and /dev/disk/by-id/… syntaxes,
• resolves paths to a canonical UUID with blkid,
• emits ‘cryptomount -u <uuid>’ when possible,
• falls back to ‘cryptomount -a’ only if no UUID can be extracted.
3. Keeps the previous behavior unchanged for unencrypted systems or for
installations that already worked.
Result: snapshot menu is produced and boots correctly on standard
(setup with inline header), detached-header, and by-id configurations;
no regression for existing users.
Jalopy