rare crashes in QWaylandShmBackingStore::flush

#0  0x00007937e33bd1e3 in QtWaylandClient::QWaylandShmBackingStore::flush(QWindow*, QRegion const&, QPoint const&) () from /home/tim/bin/qt-6.8/plugins/platforms/../../lib/libQt6WaylandClient.so.6
[Current thread is 1 (Thread 0x7937e64249c0 (LWP 260589))]
(gdb) bt
#0  0x00007937e33bd1e3 in QtWaylandClient::QWaylandShmBackingStore::flush(QWindow*, QRegion const&, QPoint const&) () at /home/tim/bin/qt-6.8/plugins/platforms/../../lib/libQt6WaylandClient.so.6
#1  0x00007937e79bad09 in QBackingStore::flush(QRegion const&, QWindow*, QPoint const&) () at /home/tim/bin/qt-6.8/lib/libQt6Gui.so.6
#2  0x00007937e835fa35 in QWidgetRepaintManager::flush(QWidget*, QRegion const&, QPlatformTextureList*) () at /home/tim/bin/qt-6.8/lib/libQt6Widgets.so.6
#3  0x00007937e83626db in QWidgetRepaintManager::flush() () at /home/tim/bin/qt-6.8/lib/libQt6Widgets.so.6
#4  0x00007937e836189a in QWidgetRepaintManager::paintAndFlush() () at /home/tim/bin/qt-6.8/lib/libQt6Widgets.so.6
#5  0x00007937e835f34a in QWidgetRepaintManager::sync(QWidget*, QRegion const&) () at /home/tim/bin/qt-6.8/lib/libQt6Widgets.so.6
#6  0x00007937e83697f4 in QWidgetWindow::handleExposeEvent(QExposeEvent*) () at /home/tim/bin/qt-6.8/lib/libQt6Widgets.so.6
#7  0x00007937e8366144 in QWidgetWindow::event(QEvent*) () at /home/tim/bin/qt-6.8/lib/libQt6Widgets.so.6
#8  0x00007937e82e880d in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /home/tim/bin/qt-6.8/lib/libQt6Widgets.so.6
#9  0x00007937e82e9966 in QApplication::notify(QObject*, QEvent*) () at /home/tim/bin/qt-6.8/lib/libQt6Widgets.so.6
#10 0x00007937e6d0fbff in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /home/tim/bin/qt-6.8/lib/libQt6Core.so.6
#11 0x00007937e79311da in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) () at /home/tim/bin/qt-6.8/lib/libQt6Gui.so.6
#12 0x00007937e79a235a in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /home/tim/bin/qt-6.8/lib/libQt6Gui.so.6
#13 0x00007937e7e6f1a1 in userEventSourceDispatch(_GSource*, int (*)(void*), void*) () at /home/tim/bin/qt-6.8/lib/libQt6Gui.so.6
#14 0x00007937e7110397 in ??? () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007937e7170dc7 in ??? () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#16 0x00007937e710f8b3 in g_main_context_iteration () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#17 0x00007937e70267de in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /home/tim/bin/qt-6.8/lib/libQt6Core.so.6
#18 0x00007937e6d1cb96 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /home/tim/bin/qt-6.8/lib/libQt6Core.so.6
#19 0x00007937e6d103fb in QCoreApplication::exec() () at /home/tim/bin/qt-6.8/lib/libQt6Core.so.6
#20 0x0000651ba2cf84f5 in main ()

[1857417.380] {Display Queue} wl_display#1.delete_id(53)
[1857419.101]  -> wl_surface#42.frame(new id wl_callback#53)
[1857419.111] {Default Queue}  -> wl_surface#42.offset(0, 0)
[1857419.113] {Default Queue}  -> wl_surface#42.attach(wl_buffer#47, 0, 0)
[1857419.116] {Default Queue}  -> wl_surface#42.damage_buffer(758, 102, 2328, 724)
[1857419.118] {Default Queue}  -> wl_surface#42.commit()
[1857419.254] {Default Queue} xdg_popup#67.repositioned(1)
[1857419.258] {Default Queue} xdg_popup#67.repositioned(2)
[1857419.259] {Default Queue} wl_surface#57.preferred_buffer_scale(2)
[1857419.267] {Default Queue}  -> wp_viewport#68.set_destination(82, 91)
[1857419.268] {Default Queue} wl_surface#57.preferred_buffer_transform(0)
[1857419.270] {Default Queue}  -> wl_surface#57.set_buffer_transform(0)
[1857419.272] {Default Queue} xdg_popup#67.configure(688, 225, 82, 91)
[1857419.274] {Default Queue} xdg_surface#56.configure(82516)
[1857419.277] {Default Queue}  -> wp_viewport#68.set_destination(82, 91)
[1857419.280] {Default Queue}  -> xdg_surface#56.ack_configure(82516)
[1857419.281] {Default Queue}  -> xdg_surface#56.set_window_geometry(0, 0, 82, 91)
[1857419.301] {Default Queue}  -> xdg_popup#67.destroy()
[1857419.303] {Default Queue}  -> xdg_surface#56.destroy()
[1857419.305] {Default Queue}  -> wl_surface#57.destroy()
[1857419.309] {Default Queue}  -> wp_viewport#68.destroy()
[1857422.044] {Default Queue}  -> wl_surface#42.offset(0, 0)
[1857422.058] {Default Queue}  -> wl_surface#42.attach(wl_buffer#61, 0, 0)
[1857422.061] {Default Queue}  -> wl_surface#42.damage_buffer(3086, 102, 28, 498)
[1857422.064] {Default Queue}  -> wl_surface#42.damage_buffer(3646, 102, 1474, 498)
[1857422.066] {Default Queue}  -> wl_surface#42.damage_buffer(3086, 600, 28, 90)
[1857422.068] {Default Queue}  -> wl_surface#42.damage_buffer(3086, 690, 28, 136)
[1857422.070] {Default Queue}  -> wl_surface#42.damage_buffer(3646, 690, 1474, 136)
[1857422.072] {Default Queue}  -> wl_surface#42.commit()
[1]    260589 segmentation fault (core dumped)