Comment 21 for bug 2004130

The failure on bionic/arm64 is unrelated:

autopkgtest for ubuntu-advantage-tools/unknown: arm64: Regression ♻

(...)
Installing for arm64-efi platform.
grub-install: error: efibootmgr: not found.
Failed: grub-install --target=arm64-efi
WARNING: Bootloader is not properly installed, system may not be bootable
Sourcing file `/etc/default/grub'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.15.0-202-generic
Found initrd image: /boot/initrd.img-4.15.0-202-generic
Adding boot menu entry for EFI firmware configuration
done
Setting up grub-efi-arm64-signed (1.187.2~18.04.1+2.06-2ubuntu14) ...
Installing for arm64-efi platform.
grub-install: error: efibootmgr: not found.
dpkg: error processing package grub-efi-arm64-signed (--configure):
 installed grub-efi-arm64-signed package post-installation script subprocess returned error exit status 1
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
Errors were encountered while processing:
 grub-efi-arm64-signed
E: Sub-process /usr/bin/dpkg returned an error code (1)
autopkgtest [12:49:06]: ERROR: erroneous package: testbed setup commands failed with status 100
blame:
badpkg: testbed setup commands failed with status 100

It was highlighted on #ubuntu-devel irc[1] and is being discussed.

Looks like the bug is https://bugs.launchpad.net/ubuntu/+source/grub2-signed/+bug/1936857

1. https://irclogs.ubuntu.com/2023/02/01/%23ubuntu-devel.html#t17:29