In-place upgrade of single TemplateVM to 4.2 to fix audio

I am on 4.2.1. I did an in-place upgrade some time ago.
Today, I noticed that some AppVMs are wired for audio, others not, depending on the template VM: debian-12-xfce and kicksecure-17 works, but my customized templates based on debian-12-min do not.

A case in point: debian-12-min-enhanced which mysteriously, the reasons for which are lost in the dim past, I neglected to upgrade to 4.2. For instance, the pipewire-qubes package is a 4.1.something version. If I attempt to spin up the template and run apt install pipewire-qubes it tells me it cannot find the package.

How does one go about upgrading a template from 4.1 to 4.2?

I have tried installing qubes-dist-upgrade on dom0 but there is none available for 4.2. Makes sense.

As I am sufficiently uninformed and wildly careless, I decided to attempt to resolve the issue myself. If I were smart, I would have cloned the template first, but I do have recent backups of the template, so I winged it.

I spun up a terminal on sys-firewall and did:

qvm-copy /etc/apt/sources.list.d/qubes-r4.list 
qvm-copy /usr/share/keyrings

I then switched to my running debian-12-min-enhanced template.

mv /home/user/QubesIncoming/sys-firewall/qubes-r4.list /etc/apt/sources.list.d/qubes-r4.list
mv /usr/share/keyrings/ /usr/share/keyrings.orig
mv /home/user/QubesIncoming/sys-firewall/keyrings/ /usr/share
apt update
apt dist-upgrade
apt autoremove
systemctl reboot

That did it! The dom0 Audio control app now indicates that the running debian-12-min-enhanced is wired for audio.

Hopefully, this might be of use to someone. Don’t be as careless as me, though. Clone any templates first to ensure easy recovery from stuff-ups.

now I can get back to watching the stuff which took me down this path…

watched it and decided to remove the link. It was sort of a sales pitch, and not appropriate for my gentle fellow qubians.