Bug#1091358: mumble: crashes on startup with pipewire backtrace

[Chris Knadle]

Hello Phillip.

The 'recommends' alternatives would need to include pipewire, pulse, 
jack, and ALSA, (Mumble has supported all of these), and not sure what 
else. And because of that I think the recommends wouldn't work, because 
pulseaudio alone would satisfy the recommends, which I believe is the 
situation here.

I've looked at the build dependencies for the newer Mumble and it also 
doesn't include any dependencies on pipewire.

https://github.com/mumble-voip/mumble/blob/master/docs/dev/build-instructions/build_linux.md

I was going to say pipewire should have a dependency on pipewire-bin -- 
but it already does. Pipewire-pulse, though, does not have a dependency 
on pipewire-bin. So maybe that's what's going on -- that pulse is the 
only audio backend in use, with a pipewire compatibility which doesn't 
load the pipewire configuration package because it's not actually in 
use. A few months ago I was using a Debian system running pulse with 
pipewire-pulse loaded and not pipewire, and I was having audio problems. 
I ended up having to switch to pipewire "wholesale" to get audio working 
well, because at the time I remember pulseaudio and pipewire conflicting.

Now looking at my local system I'm a bit more confused, because several 
VMs I'm using have pipewire as well as pulseaudio loaded at the same time.
However given the difficulty run into with this bug, I can sort of see 
why running both would be needed.

It feels like we need more information and more discussion with those 
more familiar with audio libraries and dependencies to get somewhere 
with this.

    -- Chris

Chris Knadle
Chris.Knadle at coredump.us

On 1/2/25 11:32, Philipp Kern wrote:
> Control: tag -1 - unreproducible
>
> Hi,
>
> On 1/1/25 7:47 AM, Chris Knadle wrote:
>> A further clue is that there's an error of file client.conf missing. 
>> I searched the VM running mumble and it looks like it should be:
>>
>>      /usr/share/pipewire/client.conf
>>
>> That should be in the 'pipewire-bin' package, which the 'pipewire' 
>> package depends on. Please do a quick check that these two packages 
>> are installed locally. [If you're running pipewire I can't imagine 
>> either of these wouldn't be installed.]
>
> Looks like this dependency/recommends is missing then. mumble indeed 
> starts if pipewire-bin is installed, which is not a dependency on 
> anything in KDE, nor by mumble itself.
>
> I installed these packages:
>
>> Installing:
>>   pipewire-bin
>>
>> Installing dependencies:
>>   libconfig++9v5  libglibmm-2.4-1t64  libpipewire-0.3-modules 
>> libsigc++-2.0-0v5     libxml++2.6-2v5  pipewire-pulse
>>   libffado2       libopenfec1         libroc0.4 libwireplumber-0.5-0  
>> pipewire         wireplumber
>
> Then it worked. This seems to imply that there is something broken in 
> mumble where it loads the pipewire library that is installed but fails 
> because the config is not there?
>
> When I remove pipewire-bin, it removes these:
>
>> REMOVING:
>>   pipewire  pipewire-bin  pipewire-pulse  wireplumber
>
> When I then delete ~/.config/Mumble it segfaults again. With it 
> already created, it starts.
>
> When I remove pipewire-bin and call mumble with the config already 
> created, it segfaults on exit. (I have not tried actually connecting 
> to a server and doing the talking.)
>
>> The other thing I notice are strange directories, such as 
>> ./src/mumble/ PipeWire.cpp. Is this crash the result of running 
>> mumble from a local build, rather than from the binary Debian package?
>
> No, I used debuginfod.debian.net, but it was from the package.
>
> Kind regards
> Philipp Kern