bug#50566: [core-updates-frozen] Grub fails to decrypt LUKS partition (cryptomount not found)

[Jonathan Brielmaier]

Hi folks,

today I finally got my system reconfiguring on core-updates-frozen with
almost all packages I use (minus telegram-desktop, josm and lilypond).
But when I rebooted my PC it got stuck in the grub rescue console :(

```
Welcome to GRUB!

Unkown command 'crpytomount'.
error: disk 'cryptouuid/ad06...' not found.
Entering rescue mode...
[...]
grub rescue> crpytomount -u ad06...
Unknown command 'cryptomount'.
[...]
grub rescue> set
cmdpath=(hd0)/EFI/Guix
prefix=(cryptouuid)/ad06...)/boot/grub
root=cryptouuid/ad06...
```

commit: d1732a007fff1549fd49bae595ef9541bea2a332 (pulled from)
arch: x86_66
config:
```
  (bootloader
    (bootloader-configuration
      (bootloader grub-efi-bootloader)
      (target "/boot/efi")
      (keyboard-layout keyboard-layout)))
  (mapped-devices
    (list (mapped-device
            (source (uuid "ad069897-6b43-4607-b5e9-3f00f9af74aa"))
            (target "cryptroot")
            (type luks-device-mapping))))
  (file-systems
    (append (list
             (file-system
              (mount-point "/boot/efi")
              (device (uuid "2954-F644" 'fat32))
              (type "vfat"))
             (file-system
              (device "/dev/mapper/cryptroot")
              (mount-point "/")
              (type "ext4")
              (dependencies mapped-devices))
             (file-system
              (mount-point "/media/jonathan/arbeit")
              (device (uuid "094e6082-fae5-4ba9-ad94-1a4b6d04a094"))
              (type "ext4")))
            %base-file-systems))
```

I have reconfigured the same system on master two or three days ago. The
reboot back then was successful.

I'll try to collect more information later today...

~Jonathan