I think I have a solution for this issue. I made a Kali template from debian-11 clone, switching repos to debian-12 (testing or something like that), adding kali repo keys and repos, install kali packages (as far as I remembeer I used kali-large metapackage).
For me, this worked (do this inside “faulty” kali template):
sudo apt update
sudo apt-mark unhold qubes-gui-agent
sudo apt reinstall qubes-gui-agent
sudo apt update
sudo apt upgrade
Note: If you did not previously hold the qubes-gui-agent
with apt-mark
, just skip that step.
This will reinstall qubes-gui-agent
from deb11 repo to deb12 repository. After this I am able to update kali template as usually.