I'm getting the exact same crash on krfb-24.02.0. (qt6)

/usr/lib/gcc/x86_64-pc-linux-gnu/13/include/g++-v13/optional:477: constexpr _Tp& std::_Optional_base_impl<_Tp, _Dp>::_M_get() [with _Tp = PipeWireCursor; _Dp = std::_Optional_base<PipeWireCursor, false, false>]: Assertion 'this->_M_is_engaged()' failed.

Thread 1 "krfb-virtualmon" received signal SIGABRT, Aborted.
__pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0)
    at pthread_kill.c:44
warning: 44     pthread_kill.c: No such file or directory
(gdb) bt
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0)
    at pthread_kill.c:44
#1  0x00007ffff70fa373 in __pthread_kill_internal (signo=6, threadid=<optimized out>)
    at pthread_kill.c:78
#2  0x00007ffff70a88c6 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007ffff70908b7 in __GI_abort () at abort.c:79
#4  0x00007ffff5f1072f in std::__glibcxx_assert_fail (file=<optimized out>, line=<optimized out>, 
    function=<optimized out>, condition=<optimized out>)
    at /var/tmp/portage/sys-devel/gcc-13.2.0/work/gcc-13.2.0/libstdc++-v3/src/c++11/debug.cc:61
#5  0x00007fffea3ec4b3 in PWFrameBuffer::cursorPosition() ()
   from /usr/lib64/qt6/plugins/krfb/framebuffer/pw.so
#6  0x0000555555569f29 in RfbServerManager::updateScreens() ()
#7  0x00007ffff639e0f6 in void doActivate<false>(QObject*, int, void**) ()
   from /usr/lib64/libQt6Core.so.6
#8  0x00007ffff63ae22e in QTimer::timeout(QTimer::QPrivateSignal) () from /usr/lib64/libQt6Core.so.6
#9  0x00007ffff639414f in QObject::event(QEvent*) () from /usr/lib64/libQt6Core.so.6
#10 0x00007ffff75024f9 in QApplicationPrivate::notify_helper(QObject*, QEvent*) ()
   from /usr/lib64/libQt6Widgets.so.6
#11 0x00007ffff6342738 in QCoreApplication::notifyInternal2(QObject*, QEvent*) ()
   from /usr/lib64/libQt6Core.so.6
#12 0x00007ffff64cf720 in QTimerInfoList::activateTimers() () from /usr/lib64/libQt6Core.so.6
#13 0x00007ffff65d2901 in timerSourceDispatch(_GSource*, int (*)(void*), void*) ()
   from /usr/lib64/libQt6Core.so.6
#14 0x00007ffff52c2ad2 in g_main_dispatch (context=0x7fffec000ef0) at ../glib-2.78.4/glib/gmain.c:3476
#15 0x00007ffff5320ff7 in g_main_context_dispatch_unlocked (context=0x7fffec000ef0)
    at ../glib-2.78.4/glib/gmain.c:4284
#16 g_main_context_iterate_unlocked.isra.0 (context=context@entry=0x7fffec000ef0, block=block@entry=1, 
    dispatch=dispatch@entry=1, self=<optimized out>) at ../glib-2.78.4/glib/gmain.c:4349
#17 0x00007ffff52c0be0 in g_main_context_iteration (context=0x7fffec000ef0, may_block=1)
    at ../glib-2.78.4/glib/gmain.c:4414
#18 0x00007ffff65d2bf0 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib64/libQt6Core.so.6
#19 0x00007ffff634eeba in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib64/libQt6Core.so.6
#20 0x00007ffff634a6ff in QCoreApplication::exec() () from /usr/lib64/libQt6Core.so.6
#21 0x000055555555da40 in main ()

*** Bug 482767 has been marked as a duplicate of this bug. ***

*** Bug 483355 has been marked as a duplicate of this bug. ***

Created attachment 167942 [details]
backtrace

Can confirm this. Krfb-virtualmonitor no longer crashes when opening it nor does it crash plasmashell but this persists.

[Copied from https://bugs.kde.org/show_bug.cgi?id=470996]
Now that it doesn't crash "automatically" any more.

I'm using remote ripple on an ipad to test the vnc connection (image quality normal, encoding I tried Raw and ZRLE so far)

> krfb-virtualmonitor --resolution 1024x768 --name [name] --password [password] --port 5900 --scale 1


I can see the new "display" in the display configuration (with the correct dimensions and everything - win!)
I try to connect with the ipad and I"m prompted for the password as expected.
As soon as I complete authentication, krfb-virtualmonitor crashes:

Output:
=================================
kpipewire_dmabuf_logging: eglChooseConfig returned this many configs: 1
new client request
kf.notifications: No event config could be found for event id "UserAcceptsConnection" under notifyrc file for app "krfb-virtualmonitor"
/usr/include/c++/13.2.1/optional:477: constexpr _Tp& std::_Optional_base_impl<_Tp, _Dp>::_M_get() [with _Tp = PipeWireCursor; _Dp = std::_Optional_base<PipeWireCursor, false, false>]: Assertion 'this->_M_is_engaged()' failed.
fish: Job 1, 'krfb-virtualmonitor --resolutio…' terminated by signal SIGABRT (Abort)
==================================
and the ipad returns that the connection was shut down "gracefully"

Happy to do additional tests to assist with debugging (I'll need detailed instructions/commandlines)
System details:
Garuda Linux (updated about 20 min ago)
Kernel 6.8.2-AMD-znver3
krfb-virtualmonitor 24.02.1
plasmashell 6.0.3

I can confirm that this is still happening even on my system. The result matches the mentioned observations

Created attachment 168711 [details]
krfb-fix-crash.patch

Simple fix for this crash, works for me.
d->cursor is std::optional and it can be unset in time of calling PWFrameBuffer::cursorPosition().

@Yaroslav Sidlovsky - Would you mind to commit the patch on GitLab?
I think it will be missed here.

A possibly relevant merge request was started @ https://invent.kde.org/network/krfb/-/merge_requests/66

Git commit 6e7a5ba56966ea1b67400be9ab7c82885abb76be by Yaroslav Sidlovsky.
Committed on 22/04/2024 at 14:06.
Pushed by alexeymin into branch 'master'.

Fixed crash calling PWFrameBuffer::cursorPosition()

Return default QPoint when `d->cursor` is not set.

M  +6    -1    framebuffers/pipewire/pw_framebuffer.cpp

https://invent.kde.org/network/krfb/-/commit/6e7a5ba56966ea1b67400be9ab7c82885abb76be

Git commit d2f4b34fcbfb75ae76cca7792dd3fb66c16351fc by Alexey Minnekhanov, on behalf of Yaroslav Sidlovsky.
Committed on 22/04/2024 at 16:46.
Pushed by alexeymin into branch 'release/24.05'.

Fixed crash calling PWFrameBuffer::cursorPosition()

Return default QPoint when `d->cursor` is not set.

M  +6    -1    framebuffers/pipewire/pw_framebuffer.cpp

https://invent.kde.org/network/krfb/-/commit/d2f4b34fcbfb75ae76cca7792dd3fb66c16351fc

Thought I'd check again after some other KDE updates, but still getting similar results:
Garuda linux 
6.6.29-1-lts #1 SMP PREEMPT_DYNAMIC Sat, 27 Apr 2024 18:43:45 +0000 x86_64 GNU/Linux
krfb-virtualmonitor 24.02.2
[any other info required? please ask!]

_______________________
> krfb-virtualmonitor --resolution 1024x768 --name ipad --password ipad --port 5900 --scale 1
kpipewire_dmabuf_logging: eglChooseConfig returned this many configs: 1
new client request
kf.notifications: No event config could be found for event id "UserAcceptsConnection" under notifyrc file for app "krfb-virtualmonitor"
/usr/include/c++/13.2.1/optional:477: constexpr _Tp& std::_Optional_base_impl<_Tp, _Dp>::_M_get() [with _Tp = PipeWireCursor; _Dp = std::_Optional_base<PipeWireCursor, false, false>]: Assertion 'this->_M_is_engaged()' failed.
fish: Job 1, 'krfb-virtualmonitor --resolutio…' terminated by signal SIGABRT (Abort)
_______________________

A concurrently running journalctl -f:

May 03 16:20:02 Garuda krfb-virtualmonitor[1728159]: Libgcrypt warning: missing initialization - please fix the application
May 03 16:20:02 Garuda system[1]: Started Process Core Dump (PID 1729279/UID 0).
May 03 16:20:02 Garuda systemd-coredump[1729280]: [🡕] Process 1728159 (krfb-virtualmon) of user 1000 dumped core.

Stack trace of thread 1728159:
#0  0x00007a63b7aab32c n/a (libc.so.6 + 0x8d32c)
#1  0x00007a63b7a5a6c8 raise (libc.so.6 + 0x3c6c8)
#2  0x00007a63b7a424b8 abort (libc.so.6 + 0x244b8)
#3  0x00007a63b7cd1d42 _ZSt21__glibcxx_assert_failPKciS0_S0_ (libstdc++.so.6 + 0xd1d42)
#4  0x00007a63b0578e9c n/a (pw.so + 0x8e9c)
#5  0x00005bed95a59309 n/a (krfb-virtualmonitor + 0x13309)
#6  0x00007a63b8197679 n/a (libQt6Core.so.6 + 0x197679)
#7  0x00007a63b819cdf4 _ZN6QTimer10timerEventEP11QTimerEvent (libQt6Core.so.6 + 0x19cdf4)
#8  0x00007a63b81883f6 _ZN7QObject5eventEP6QEvent (libQt6Core.so.6 + 0x1883f6)
#9  0x00007a63b90fbfcb _ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent (libQt6Widgets.so.6 + 0xfbfcb)
#10 0x00007a63b813db38 _ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent (libQt6Core.so.6 + 0x13db38)
#11 0x00007a63b82ab95d _ZN14QTimerInfoList14activateTimersEv (libQt6Core.so.6 + 0x2ab95d)
#12 0x00007a63b8385f8c n/a (libQt6Core.so.6 + 0x385f8c)
#13 0x00007a63b7175199 n/a (libglib-2.0.so.0 + 0x5a199)
#14 0x00007a63b71d43bf n/a (libglib-2.0.so.0 + 0xb93bf)
#15 0x00007a63b7174712 g_main_context_iteration (libglib-2.0.so.0 + 0x59712)
#16 0x00007a63b8383e64 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x383e64)
#17 0x00007a63b8145cce _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x145cce)
#18 0x00007a63b8141738 _ZN16QCoreApplication4execEv (libQt6Core.so.6 + 0x141738)
#19 0x00005bed95a4e0ad n/a (krfb-virtualmonitor + 0x80ad)
#20 0x00007a63b7a43cd0 n/a (libc.so.6 + 0x25cd0)
#21 0x00007a63b7a43d8a __libc_start_main (libc.so.6 + 0x25d8a)
#22 0x00005bed95a4ed75 n/a (krfb-virtualmonitor + 0x8d75)

Stack trace of thread 1728177:
#0  0x00007a63b7b26e86 epoll_wait (libc.so.6 + 0x108e86)
#1  0x00007a63ab6b9cf9 n/a (libspa-support.so + 0x14cf9)
#2  0x00007a63ab6ab58d n/a (libspa-support.so + 0x658d)
#3  0x00007a639bf60162 n/a (libpipewire-0.3.so.0 + 0x1c162)
#4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728183:
#0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
#1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
#2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
#3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
#4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728165:
#0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
#1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
#2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
#3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
#4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728184:
#0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
#1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
#2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
#3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
#4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728161:
#0  0x00007a63b7b190df __poll (libc.so.6 + 0xfb0df)
#1  0x00007a63b361dce8 n/a (libQt6WaylandClient.so.6 + 0x64ce8)
#2  0x00007a63b82add73 n/a (libQt6Core.so.6 + 0x2add73)
#3  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#4  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728162:
#0  0x00007a63b7b190df __poll (libc.so.6 + 0xfb0df)
#1  0x00007a63b361dce8 n/a (libQt6WaylandClient.so.6 + 0x64ce8)
#2  0x00007a63b82add73 n/a (libQt6Core.so.6 + 0x2add73)
#3  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#4  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728160:
#0  0x00007a63b7b190df __poll (libc.so.6 + 0xfb0df)
#1  0x00007a63b71d4306 n/a (libglib-2.0.so.0 + 0xb9306)
#2  0x00007a63b7174712 g_main_context_iteration (libglib-2.0.so.0 + 0x59712)
#3  0x00007a63b8383e64 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x383e64)
#4  0x00007a63b8145cce _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x145cce)
#5  0x00007a63b822cc4f _ZN7QThread4execEv (libQt6Core.so.6 + 0x22cc4f)
#6  0x00007a63b7f7515f n/a (libQt6DBus.so.6 + 0x2c15f)
#7  0x00007a63b82add73 n/a (libQt6Core.so.6 + 0x2add73)
#8  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#9  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728164:
#0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
#1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
#2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
#3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
#4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728182:
#0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
#1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
#2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
#3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
#4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728168:
#0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
#1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
#2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
#3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
#4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728163:
#0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
#1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
#2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
#3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
#4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728166:
#0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
#1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
#2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
#3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
#4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)

Stack trace of thread 1728167:
#0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
#1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
#2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
#3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
#4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
#5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
ELF object binary architecture: AMD x86-64
May 03 16:20:02 Garuda system[1]: systemd-coredump@5-1729279-0.service: Deactivated successfully.
_______________________

HTH!

(In reply to ian+bugs.kde.org from comment #12)
> Thought I'd check again after some other KDE updates, but still getting
> similar results:
> Garuda linux 
> 6.6.29-1-lts #1 SMP PREEMPT_DYNAMIC Sat, 27 Apr 2024 18:43:45 +0000 x86_64
> GNU/Linux
> krfb-virtualmonitor 24.02.2
> [any other info required? please ask!]
> 
> _______________________
> > krfb-virtualmonitor --resolution 1024x768 --name ipad --password ipad --port 5900 --scale 1
> kpipewire_dmabuf_logging: eglChooseConfig returned this many configs: 1
> new client request
> kf.notifications: No event config could be found for event id
> "UserAcceptsConnection" under notifyrc file for app "krfb-virtualmonitor"
> /usr/include/c++/13.2.1/optional:477: constexpr _Tp&
> std::_Optional_base_impl<_Tp, _Dp>::_M_get() [with _Tp = PipeWireCursor; _Dp
> = std::_Optional_base<PipeWireCursor, false, false>]: Assertion
> 'this->_M_is_engaged()' failed.
> fish: Job 1, 'krfb-virtualmonitor --resolutio…' terminated by signal SIGABRT
> (Abort)
> _______________________
> 
> A concurrently running journalctl -f:
> 
> May 03 16:20:02 Garuda krfb-virtualmonitor[1728159]: Libgcrypt warning:
> missing initialization - please fix the application
> May 03 16:20:02 Garuda system[1]: Started Process Core Dump (PID 1729279/UID
> 0).
> May 03 16:20:02 Garuda systemd-coredump[1729280]: [🡕] Process 1728159
> (krfb-virtualmon) of user 1000 dumped core.
> 
> Stack trace of thread 1728159:
> #0  0x00007a63b7aab32c n/a (libc.so.6 + 0x8d32c)
> #1  0x00007a63b7a5a6c8 raise (libc.so.6 + 0x3c6c8)
> #2  0x00007a63b7a424b8 abort (libc.so.6 + 0x244b8)
> #3  0x00007a63b7cd1d42 _ZSt21__glibcxx_assert_failPKciS0_S0_ (libstdc++.so.6
> + 0xd1d42)
> #4  0x00007a63b0578e9c n/a (pw.so + 0x8e9c)
> #5  0x00005bed95a59309 n/a (krfb-virtualmonitor + 0x13309)
> #6  0x00007a63b8197679 n/a (libQt6Core.so.6 + 0x197679)
> #7  0x00007a63b819cdf4 _ZN6QTimer10timerEventEP11QTimerEvent
> (libQt6Core.so.6 + 0x19cdf4)
> #8  0x00007a63b81883f6 _ZN7QObject5eventEP6QEvent (libQt6Core.so.6 +
> 0x1883f6)
> #9  0x00007a63b90fbfcb
> _ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent
> (libQt6Widgets.so.6 + 0xfbfcb)
> #10 0x00007a63b813db38
> _ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent (libQt6Core.so.6 +
> 0x13db38)
> #11 0x00007a63b82ab95d _ZN14QTimerInfoList14activateTimersEv
> (libQt6Core.so.6 + 0x2ab95d)
> #12 0x00007a63b8385f8c n/a (libQt6Core.so.6 + 0x385f8c)
> #13 0x00007a63b7175199 n/a (libglib-2.0.so.0 + 0x5a199)
> #14 0x00007a63b71d43bf n/a (libglib-2.0.so.0 + 0xb93bf)
> #15 0x00007a63b7174712 g_main_context_iteration (libglib-2.0.so.0 + 0x59712)
> #16 0x00007a63b8383e64
> _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEvents
> FlagEE (libQt6Core.so.6 + 0x383e64)
> #17 0x00007a63b8145cce _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE
> (libQt6Core.so.6 + 0x145cce)
> #18 0x00007a63b8141738 _ZN16QCoreApplication4execEv (libQt6Core.so.6 +
> 0x141738)
> #19 0x00005bed95a4e0ad n/a (krfb-virtualmonitor + 0x80ad)
> #20 0x00007a63b7a43cd0 n/a (libc.so.6 + 0x25cd0)
> #21 0x00007a63b7a43d8a __libc_start_main (libc.so.6 + 0x25d8a)
> #22 0x00005bed95a4ed75 n/a (krfb-virtualmonitor + 0x8d75)
> 
> Stack trace of thread 1728177:
> #0  0x00007a63b7b26e86 epoll_wait (libc.so.6 + 0x108e86)
> #1  0x00007a63ab6b9cf9 n/a (libspa-support.so + 0x14cf9)
> #2  0x00007a63ab6ab58d n/a (libspa-support.so + 0x658d)
> #3  0x00007a639bf60162 n/a (libpipewire-0.3.so.0 + 0x1c162)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728183:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728165:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728184:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728161:
> #0  0x00007a63b7b190df __poll (libc.so.6 + 0xfb0df)
> #1  0x00007a63b361dce8 n/a (libQt6WaylandClient.so.6 + 0x64ce8)
> #2  0x00007a63b82add73 n/a (libQt6Core.so.6 + 0x2add73)
> #3  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #4  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728162:
> #0  0x00007a63b7b190df __poll (libc.so.6 + 0xfb0df)
> #1  0x00007a63b361dce8 n/a (libQt6WaylandClient.so.6 + 0x64ce8)
> #2  0x00007a63b82add73 n/a (libQt6Core.so.6 + 0x2add73)
> #3  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #4  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728160:
> #0  0x00007a63b7b190df __poll (libc.so.6 + 0xfb0df)
> #1  0x00007a63b71d4306 n/a (libglib-2.0.so.0 + 0xb9306)
> #2  0x00007a63b7174712 g_main_context_iteration (libglib-2.0.so.0 + 0x59712)
> #3  0x00007a63b8383e64
> _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEvents
> FlagEE (libQt6Core.so.6 + 0x383e64)
> #4  0x00007a63b8145cce _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE
> (libQt6Core.so.6 + 0x145cce)
> #5  0x00007a63b822cc4f _ZN7QThread4execEv (libQt6Core.so.6 + 0x22cc4f)
> #6  0x00007a63b7f7515f n/a (libQt6DBus.so.6 + 0x2c15f)
> #7  0x00007a63b82add73 n/a (libQt6Core.so.6 + 0x2add73)
> #8  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #9  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728164:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728182:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728168:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728163:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728166:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728167:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> ELF object binary architecture: AMD x86-64
> May 03 16:20:02 Garuda system[1]: systemd-coredump@5-1729279-0.service:
> Deactivated successfully.
> _______________________
> 
> HTH!

What package version? Please contact package maintainer to clarify the situation.(In reply to ian+bugs.kde.org from comment #12)
> Thought I'd check again after some other KDE updates, but still getting
> similar results:
> Garuda linux 
> 6.6.29-1-lts #1 SMP PREEMPT_DYNAMIC Sat, 27 Apr 2024 18:43:45 +0000 x86_64
> GNU/Linux
> krfb-virtualmonitor 24.02.2
> [any other info required? please ask!]
> 
> _______________________
> > krfb-virtualmonitor --resolution 1024x768 --name ipad --password ipad --port 5900 --scale 1
> kpipewire_dmabuf_logging: eglChooseConfig returned this many configs: 1
> new client request
> kf.notifications: No event config could be found for event id
> "UserAcceptsConnection" under notifyrc file for app "krfb-virtualmonitor"
> /usr/include/c++/13.2.1/optional:477: constexpr _Tp&
> std::_Optional_base_impl<_Tp, _Dp>::_M_get() [with _Tp = PipeWireCursor; _Dp
> = std::_Optional_base<PipeWireCursor, false, false>]: Assertion
> 'this->_M_is_engaged()' failed.
> fish: Job 1, 'krfb-virtualmonitor --resolutio…' terminated by signal SIGABRT
> (Abort)
> _______________________
> 
> A concurrently running journalctl -f:
> 
> May 03 16:20:02 Garuda krfb-virtualmonitor[1728159]: Libgcrypt warning:
> missing initialization - please fix the application
> May 03 16:20:02 Garuda system[1]: Started Process Core Dump (PID 1729279/UID
> 0).
> May 03 16:20:02 Garuda systemd-coredump[1729280]: [🡕] Process 1728159
> (krfb-virtualmon) of user 1000 dumped core.
> 
> Stack trace of thread 1728159:
> #0  0x00007a63b7aab32c n/a (libc.so.6 + 0x8d32c)
> #1  0x00007a63b7a5a6c8 raise (libc.so.6 + 0x3c6c8)
> #2  0x00007a63b7a424b8 abort (libc.so.6 + 0x244b8)
> #3  0x00007a63b7cd1d42 _ZSt21__glibcxx_assert_failPKciS0_S0_ (libstdc++.so.6
> + 0xd1d42)
> #4  0x00007a63b0578e9c n/a (pw.so + 0x8e9c)
> #5  0x00005bed95a59309 n/a (krfb-virtualmonitor + 0x13309)
> #6  0x00007a63b8197679 n/a (libQt6Core.so.6 + 0x197679)
> #7  0x00007a63b819cdf4 _ZN6QTimer10timerEventEP11QTimerEvent
> (libQt6Core.so.6 + 0x19cdf4)
> #8  0x00007a63b81883f6 _ZN7QObject5eventEP6QEvent (libQt6Core.so.6 +
> 0x1883f6)
> #9  0x00007a63b90fbfcb
> _ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent
> (libQt6Widgets.so.6 + 0xfbfcb)
> #10 0x00007a63b813db38
> _ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent (libQt6Core.so.6 +
> 0x13db38)
> #11 0x00007a63b82ab95d _ZN14QTimerInfoList14activateTimersEv
> (libQt6Core.so.6 + 0x2ab95d)
> #12 0x00007a63b8385f8c n/a (libQt6Core.so.6 + 0x385f8c)
> #13 0x00007a63b7175199 n/a (libglib-2.0.so.0 + 0x5a199)
> #14 0x00007a63b71d43bf n/a (libglib-2.0.so.0 + 0xb93bf)
> #15 0x00007a63b7174712 g_main_context_iteration (libglib-2.0.so.0 + 0x59712)
> #16 0x00007a63b8383e64
> _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEvents
> FlagEE (libQt6Core.so.6 + 0x383e64)
> #17 0x00007a63b8145cce _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE
> (libQt6Core.so.6 + 0x145cce)
> #18 0x00007a63b8141738 _ZN16QCoreApplication4execEv (libQt6Core.so.6 +
> 0x141738)
> #19 0x00005bed95a4e0ad n/a (krfb-virtualmonitor + 0x80ad)
> #20 0x00007a63b7a43cd0 n/a (libc.so.6 + 0x25cd0)
> #21 0x00007a63b7a43d8a __libc_start_main (libc.so.6 + 0x25d8a)
> #22 0x00005bed95a4ed75 n/a (krfb-virtualmonitor + 0x8d75)
> 
> Stack trace of thread 1728177:
> #0  0x00007a63b7b26e86 epoll_wait (libc.so.6 + 0x108e86)
> #1  0x00007a63ab6b9cf9 n/a (libspa-support.so + 0x14cf9)
> #2  0x00007a63ab6ab58d n/a (libspa-support.so + 0x658d)
> #3  0x00007a639bf60162 n/a (libpipewire-0.3.so.0 + 0x1c162)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728183:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728165:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728184:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728161:
> #0  0x00007a63b7b190df __poll (libc.so.6 + 0xfb0df)
> #1  0x00007a63b361dce8 n/a (libQt6WaylandClient.so.6 + 0x64ce8)
> #2  0x00007a63b82add73 n/a (libQt6Core.so.6 + 0x2add73)
> #3  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #4  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728162:
> #0  0x00007a63b7b190df __poll (libc.so.6 + 0xfb0df)
> #1  0x00007a63b361dce8 n/a (libQt6WaylandClient.so.6 + 0x64ce8)
> #2  0x00007a63b82add73 n/a (libQt6Core.so.6 + 0x2add73)
> #3  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #4  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728160:
> #0  0x00007a63b7b190df __poll (libc.so.6 + 0xfb0df)
> #1  0x00007a63b71d4306 n/a (libglib-2.0.so.0 + 0xb9306)
> #2  0x00007a63b7174712 g_main_context_iteration (libglib-2.0.so.0 + 0x59712)
> #3  0x00007a63b8383e64
> _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEvents
> FlagEE (libQt6Core.so.6 + 0x383e64)
> #4  0x00007a63b8145cce _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE
> (libQt6Core.so.6 + 0x145cce)
> #5  0x00007a63b822cc4f _ZN7QThread4execEv (libQt6Core.so.6 + 0x22cc4f)
> #6  0x00007a63b7f7515f n/a (libQt6DBus.so.6 + 0x2c15f)
> #7  0x00007a63b82add73 n/a (libQt6Core.so.6 + 0x2add73)
> #8  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #9  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728164:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728182:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728168:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728163:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728166:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> 
> Stack trace of thread 1728167:
> #0  0x00007a63b7aa5ebe n/a (libc.so.6 + 0x87ebe)
> #1  0x00007a63b7aa8750 pthread_cond_wait (libc.so.6 + 0x8a750)
> #2  0x00007a63a94863fc n/a (radeonsi_dri.so + 0x863fc)
> #3  0x00007a63a949ec2c n/a (radeonsi_dri.so + 0x9ec2c)
> #4  0x00007a63b7aa955a n/a (libc.so.6 + 0x8b55a)
> #5  0x00007a63b7b26a5c n/a (libc.so.6 + 0x108a5c)
> ELF object binary architecture: AMD x86-64
> May 03 16:20:02 Garuda system[1]: systemd-coredump@5-1729279-0.service:
> Deactivated successfully.
> _______________________
> 
> HTH!

Either ask package maintainer to include patch in package or wait for update to 24.02.3.