Compression type 0x3 not supported

[Ken Sharp]

Rebooted computer and was immediately greeted with:

"Compression type 0x3 not supported"

This results in an unusable system.

See https://askubuntu.com/q/1056396/ken-sharp

Checked bionic-backports but Grub 2.04 has not been backported. So a kernel that supports BTRFS ZStd compression is made available, but no Grub has been made available to boot it!

[Julian Andres Klode (juliank)]

grub 2.04 is used on UEFI systems (via grub2-unsigned and grub2-signed), so you can make this work on modern hardware. That said, that's somewhat accidental side effect of upgrading to 2.04 for UEFI, and not a conscious decision on anyone's part.

[Ken Sharp (kennybobs)]

Neither grub2-signed nor grub2-unsigned exist in the repository.
https://packages.ubuntu.com/search?suite=bionic-updates,bionic,bionic-backports&arch=amd64&searchon=names&keywords=grub2

[Dimitri John Ledkov (xnox)]

grub2-signed and grub2-unsigned are source package names.

You are searching for binary package names.... binary package name is grub-efi-amd64-signed