Extract:
Program terminated with signal SIGSEGV, Segmentation fault.
#0 QObject::parent (this=<optimized out>, this=<optimized out>) at /usr/include/qt6/QtCore/qobjectdefs.h:241
241 { return const_cast<QObject *>(cast(const_cast<const QObject *>(obj))); }
[Current thread is 1 (Thread 0x7f92c65b0080 (LWP 11703))]
#0 QObject::parent (this=<optimized out>, this=<optimized out>) at /usr/include/qt6/QtCore/qobjectdefs.h:241
#1 Plasma::Containment::screen (this=<optimized out>)
at /usr/src/debug/libplasma/libplasma-6.5.1/src/plasma/containment.cpp:471
#2 0x000055a7fd082f4b in PanelView::canSetStrut (this=0x7f92b8007b30)
at /usr/src/debug/plasma-workspace/plasma-workspace-6.5.1/shell/panelview.cpp:1503
#3 PanelView::canSetStrut (this=0x7f92b8007b30)
at /usr/src/debug/plasma-workspace/plasma-workspace-6.5.1/shell/panelview.cpp:1479
#4 PanelView::updateExclusiveZone (this=this@entry=0x7f92b8007b30)
at /usr/src/debug/plasma-workspace/plasma-workspace-6.5.1/shell/panelview.cpp:1591
#5 0x000055a7fd0836bc in PanelView::updateFloating (this=0x7f92b8007b30)
at /usr/src/debug/plasma-workspace/plasma-workspace-6.5.1/shell/panelview.cpp:1961
#6 0x000055a7fd0a5644 in PanelView::PanelView (parent=0x0, this=0x7f92b8007b30, corona=0x7ffe9c6e26b0,
targetScreen=<optimized out>)
at /usr/src/debug/plasma-workspace/plasma-workspace-6.5.1/shell/panelview.cpp:131
#7 ShellCorona::createWaitingPanels (this=0x7ffe9c6e26b0)
at /usr/src/debug/plasma-workspace/plasma-workspace-6.5.1/shell/shellcorona.cpp:1613
#8 0x00007f92ccfd716f in QtPrivate::QSlotObjectBase::call (this=<optimized out>, r=<optimized out>,
a=<optimized out>, this=<optimized out>, r=<optimized out>, a=<optimized out>)
at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qobjectdefs_impl.h:461
#9 doActivate<false> (sender=<optimized out>, signal_index=<optimized out>, argv=<optimized out>)
at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qobject.cpp:4255
#10 0x00007f92ccfe439c in QMetaObject::activate<void, QTimer::QPrivateSignal> (sender=<optimized out>,
mo=<optimized out>, local_signal_index=0, ret=0x0)
at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qobjectdefs.h:319
#11 QTimer::timeout (this=<optimized out>, _t1=...)
at /usr/src/debug/qt6-base/build/src/corelib/Core_autogen/include/moc_qtimer.cpp:182
#12 QTimer::timerEvent (e=<optimized out>, this=<optimized out>)
at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qtimer.cpp:322
#13 QTimer::timerEvent (this=<optimized out>, e=<optimized out>)
at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qtimer.cpp:316
#14 0x00007f92ccfc44f6 in QObject::event (this=<optimized out>, e=<optimized out>)
at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qobject.cpp:1386
#15 0x00007f92cf3020a0 in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x7ffe9c6e27c0,
e=0x7ffe9c6e2010) at /usr/src/debug/qt6-base/qtbase/src/widgets/kernel/qapplication.cpp:3307
#16 0x00007f92ccf6a6c8 in QCoreApplication::notifyInternal2 (receiver=0x7ffe9c6e27c0, event=0x7ffe9c6e2010)
at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qcoreapplication.cpp:1109
#17 0x00007f92cd12c6af in QCoreApplication::sendEvent (receiver=<optimized out>, event=0x7ffe9c6e2010)
at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qcoreapplication.cpp:1549
#18 QTimerInfoList::activateTimers (this=0x55a8116a8180)
at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qtimerinfo_unix.cpp:426
#19 0x00007f92cd24dad1 in timerSourceDispatch (source=<optimized out>)
at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qeventdispatcher_glib.cpp:152
A Containment without a parent 
Worth reporting a bug for plasma-workspace.