Bug#1113738: doomsday: segfault on debian 13

[Bernhard Übelacker]

On Mon, 01 Sep 2025 15:48:27 -0600 Daniel Blaschke <blaschke at hep.itp.tuwien.ac.at> wrote:
> Package: doomsday
> Version: 2.3.1+ds1-1+b4
> Severity: grave
> Justification: renders package unusable
> X-Debbugs-Cc: blaschke at hep.itp.tuwien.ac.at
> 
> Dear Maintainer,
> 
> on a fresh debian 13 install (default gnome desktop), doomsday segfaults on start with the following error message:
> ***
> QSocketNotifier: Can only be used with threads started with QThread
> Segmentation fault
> ***
> 
> thanks,
> Daniel

Hello,
this crash seems related to using a Wayland desktop.
I get a backtrace as shown in [2] using a Plasma Wayland session.

As a workaround, please check if starting doomsday
with this command line avoids the crash:

   QT_QPA_PLATFORM=xcb doomsday

Using this environment should make Qt use the XWayland server,
and is mentioned in the upstream forum [1].

Because this shouldn't "rendering it completely unusable to everyone",
would severity important be better suited?

Kind regards,
Bernhard


[1]
https://talk.dengine.net/discussion/2972/linux-wayland
https://tracker.dengine.net/issues/2473


[2]
Thread 1 "doomsday" received signal SIGSEGV, Segmentation fault.
0x00007ffff539a1c3 in _XFlush () from /lib/x86_64-linux-gnu/libX11.so.6
(gdb) bt
#0  0x00007ffff539a1c3 in _XFlush () from /lib/x86_64-linux-gnu/libX11.so.6
#1  0x00007ffff539cec5 in _XGetRequest () from /lib/x86_64-linux-gnu/libX11.so.6
#2  0x00007ffff538f905 in XQueryExtension () from /lib/x86_64-linux-gnu/libX11.so.6
#3  0x00007ffff53823f4 in XInitExtension () from /lib/x86_64-linux-gnu/libX11.so.6
#4  0x00007ffff69090ef in XextAddDisplay () from /lib/x86_64-linux-gnu/libXext.so.6
#5  0x00007ffff68c786f in ?? () from /lib/x86_64-linux-gnu/libXrandr.so.2
#6  0x00007ffff68c7f88 in XRRQueryExtension () from /lib/x86_64-linux-gnu/libXrandr.so.2
#7  0x00007ffff7d615c7 in de::internal::RRInfo::RRInfo() () from /lib/x86_64-linux-gnu/libdeng_gui.so.2.3
#8  0x00007ffff7d60bfb in DisplayMode_Native_Init () from /lib/x86_64-linux-gnu/libdeng_gui.so.2.3
#9  0x00007ffff7cefdd9 in DisplayMode_Init () from /lib/x86_64-linux-gnu/libdeng_gui.so.2.3
#10 0x00005555557539e9 in ClientApp::initialize() ()
#11 0x00005555557352af in main ()
(gdb)