wireplumber conflicts with pipewire-media-session & needs fixing

[Jeremy Bícha]

Impact
------
Ubuntu 22.04 LTS installs pipewire-media-session by default. If a user attempts to install wireplumber, it will break the pipewire-session-manager systemd user service used by gnome-remote-desktop

Failed to preset unit, file /etc/systemd/user/pipewire-session-manager.service already exists and is a symlink to /usr/lib/systemd/user/pipewire-media-session.service.
Created symlink /etc/systemd/user/pipewire.service.wants/wireplumber.service \u2192 /usr/lib/systemd/user/wireplumber.service.
/usr/bin/deb-systemd-helper: error: systemctl preset failed on wireplumber.service: No such file or directory

More details are needed for whether the broken symlink causes any issues since pipewire appears to still work.

Test Case
---------

What Could Go Wrong
-------------------

[Rik Mills (rikmills)]

> Is it necessary for wireplumber to conflict with pipewire-media-session?
> Should we add Replaces?

wireplumber already conflicts/replaces pipewire-media-session

It was not shown in the image I posted on IRC, but pipewire-media-session was 'removed' at the start of the apt full-upgrade

Sadly it was removed and NOT purged

Currently in Kubuntu Kinetic it is required to 'apt purge pipewire-media-session' to get things working if you also remove pulseaudio to complete the pipewire switch

[Rik Mills (rikmills)]

The pipewire-media-session postrm is:

#!/bin/sh
set -e
# Automatically added by dh_installsystemduser/13.7.1ubuntu1
if [ "$1" = "remove" ]; then
 if [ -z "${DPKG_ROOT:-}" ] && [ -x "/usr/bin/deb-systemd-helper" ] ; then
  deb-systemd-helper --user mask 'pipewire-media-session.service' >/dev/null || true
 fi
fi

if [ "$1" = "purge" ]; then
 if [ -z "${DPKG_ROOT:-}" ] && [ -x "/usr/bin/deb-systemd-helper" ] ; then
  deb-systemd-helper --user purge 'pipewire-media-session.service' >/dev/null || true
  deb-systemd-helper --user unmask 'pipewire-media-session.service' >/dev/null || true
 fi
fi
# End automatically added section

[Jeremy Bícha (jbicha)]

I'm assigning this to me for tracking but I won't be able to look into this more until next week. Sorry.

[Dylan Aïssi (daissi)]

Basically, pipewire-pulse.service wants pipewire-session-manager.service.
pipewire-session-manager.service is an alias from both wireplumber.service and pipewire-media-session.service.
To avoid this conflict, we need to remove pipewire-media-session.service during the remove step of the package, not only at the purge step.

I am thinking about applying this fix. And a similar patch for wireplumber, just in case a user wants to move from wireplumber to pipewire-media-session for whatever reason.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "0001-Remove-pipewire-media-session.service-when-the-packa.patch" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issue please contact him.]

[Jeremy Bícha (jbicha)]

Dylan, thank you very much for your patch. I'm going to go ahead and upload pipewire-media-session and wireplumber to Ubuntu 22.10 now. Please see the attached patch also to apply on top of your patch.

After this issue is fixed in Debian, I need to backport the fix to Ubuntu 22.04 LTS since some people will attempt to switch to and away from pipewire there.

[Launchpad Janitor (janitor)]

This bug was fixed in the package pipewire-media-session - 0.4.1-3ubuntu1

---------------
pipewire-media-session (0.4.1-3ubuntu1) kinetic; urgency=medium

  [ Dylan Aïssi ]
  * Remove pipewire-media-session.service when the package is removed,
    not only when it is purged to avoid conflict with wireplumber.
    See https://bugs.debian.org/997818 (LP: #1977564)

  [ Jeremy Bicha ]
  * debian/postrm: Don't forget to add #DEBHELPER#

 -- Jeremy Bicha <email address hidden> Thu, 16 Jun 2022 13:53:47 -0400

[Launchpad Janitor (janitor)]

This bug was fixed in the package wireplumber - 0.4.10-2ubuntu1

---------------
wireplumber (0.4.10-2ubuntu1) kinetic; urgency=medium

  * Remove wireplumber.service when the package is removed,
    not only when it is purged to avoid conflict with pipewire-media-session.
    See https://bugs.debian.org/997818 (LP: #1977564)

 -- Jeremy Bicha <email address hidden> Thu, 16 Jun 2022 12:18:29 -0400