The Ubuntu Studio team has investigated a conflict involving upgrades from Ubuntu 22.04 to 24.04 failing. This has been confirmed to be reproducible.

We are currently following multiple bug reports (Launchpad bugs 2078639, 2078608, and 2079817) with most of them being duplicates of the first in that list.

If you have attempted to upgrade and ran into this problem, feel free to click on the first link in that list and click on “Does this bug affect you?”. Filing additional bug reports is unnecessary.

In most flavors of Ubuntu in 24.04 LTS, the idea was to have PipeWire completely replace PulseAudio as the primary sound server and would force the installation of PipeWire. However, with Ubuntu Studio, we went with a different approach of having PipeWire be the default, but be replaced by PulseAudio if the user wished to switch back to the classic, albiet unsupported, setup. This meant PipeWire had to be a “soft” dependency rather than a “hard” one so that it could be uninstalled by our metapackages without breaking the entire desktop metapackage.

However, this also made it so that the upgrade resolver (ubuntu-release-upgrader) would get confused when calculating how to perform the upgrade. This is where we are hitting the problem.

Currently, we are working with the Ubuntu Foundations Team at Canonical on how to have ubuntu-release-upgrader force an installation of PipeWire for Ubuntu Studio without Ubuntu Studio requiring a hard dependency on PipeWire.

Unfortunately, if we cannot resolve this issue, we may have to do one of two things:

• Not support direct, in-place upgrades of Ubuntu Studio 22.04 LTS to 24.04 LTS and remove the upgrade notifier.
• Create a hard dependency on PipeWire, effectively removing the ability to switch back to the classic PulseAudio/JACK bridged setup with Studio Controls.

We don’t want either of these solutions, which is why we are hoping we can find a solution with ubuntu-release-upgrader soon.