[Pkg-utopia-maintainers] Bug#997818: Bug#997818: wireplumber: Failed to preset unit, file /etc/systemd/user/pipewire-session-manager.service already exists

[Raphael Hertzog]

Hi,

On Sat, 30 Oct 2021 01:37:53 +0200 Michael Biebl <biebl at debian.org> wrote:
> 
> Am 30.10.2021 um 01:21 schrieb Laurent Bigonville:
> > That also looks RC to me, leaving a dangling symlink is never good, not 
> > too sure how to fix this.
> 
> This preserves the enablement state of the service, similar to how 
> conffiles are removed on "apt remove".
> Only if you purge a package, its conffiles are removed (and its systemd 
> enablement state)
> 
> Are you saying this is not the correct way?

I think we are not speaking of the same thing. The error message
refers to "/etc/systemd/user/pipewire-session-manager.service" and this
one is just a side-effect of the "Alias" directive.

The broken symlink that preserves the "enablement" state of the service
is /etc/systemd/user/pipewire.service.wants/pipewire-media-session.service
and this one doesn't get complained about.

To me it looks like that the symlinks created for the "alias" entries
should be removed when you remove the package if they point to the
alternative provided by the current package and it should be done
automatically by debhelper stuff. We should not have to tweak packages to
do that...

Or, probably better, the setup scripts should detect that the symlink for
the "alias" directive is currently broken and that it should take it over.
I filed this suggestion to systemd:
https://github.com/systemd/systemd/issues/23694

But in the mean time, it's certainly a good idea to manually clean it up
in pipewire-media-session preinst's "remove" to avoid this ugly error:

Paramétrage de wireplumber (0.4.10-2) ...
Failed to preset unit, file "/etc/systemd/user/pipewire-session-manager.service" already exists and is a
 symlink to "/lib/systemd/user/pipewire-media-session.service".
/usr/bin/deb-systemd-helper: error: systemctl preset failed on wireplumber.service: No such file or directory

Cheers,
-- 
Raphaël Hertzog