Thread 1 "demo" received signal SIGSEGV, Segmentation fault.
0x00007ffff7d7849e in QWidget::show() () from /usr/lib64/libQt6Widgets.so.6
(gdb) backtrace
#0  0x00007ffff7d7849e in QWidget::show() () at /usr/lib64/libQt6Widgets.so.6
#1  0x00007ffff7bcb3a6 in ??? () at /usr/lib64/libQt6Widgets.so.6
#2  0x00007ffff6b02bab in ??? () at /usr/lib64/libQt6Core.so.6
#3  0x00007ffff6a0d43f in QAbstractAnimationPrivate::setState(QAbstractAnimation::State) ()
    at /usr/lib64/libQt6Core.so.6
#4  0x00007ffff6a0d28f in QAbstractAnimationPrivate::setState(QAbstractAnimation::State) ()
    at /usr/lib64/libQt6Core.so.6
#5  0x00007ffff7c465e3 in ??? () at /usr/lib64/libQt6Widgets.so.6
#6  0x00007ffff7c50a56 in ??? () at /usr/lib64/libQt6Widgets.so.6
#7  0x00007ffff7b5fc3f in ??? () at /usr/lib64/libQt6Widgets.so.6
#8  0x00007ffff6b02e05 in ??? () at /usr/lib64/libQt6Core.so.6
#9  0x00007ffff7bba7df in QTabBar::setCurrentIndex(int) () at /usr/lib64/libQt6Widgets.so.6
#10 0x00007ffff7c72a98 in ??? () at /usr/lib64/libQt6Widgets.so.6
#11 0x00007ffff7b5ed9e in ??? () at /usr/lib64/libQt6Widgets.so.6
#12 0x0000555555558916 in MainWindow::setDefaultDockArrangement (this=0x5555559a3040)
    at /home/tobias/tmp/9/MainWindow.cpp:61
#13 0x0000555555559ab6 in QtPrivate::FunctorCall<std::integer_sequence<unsigned long>, QtPrivate::List<>, void, void (MainWindow::*)()>::call(void (MainWindow::*)(), MainWindow*, void**)::{lambda()#1}::operator()() const (__closure=0x7fffffffc160) at /usr/include/qt6/QtCore/qobjectdefs_impl.h:127
#14 0x0000555555559c2b in QtPrivate::FunctorCallBase::call_internal<void, QtPrivate::FunctorCall<std::integer_sequence<unsigned long>, QtPrivate::List<>, void, void (MainWindow::*)()>::call(void (MainWindow::*)(), MainWindow*, void**)::{lambda()#1}>(void**, QtPrivate::FunctorCall<std::integer_sequence<unsigned long>, QtPrivate::List<>, void, void (MainWindow::*)()>::call(void (MainWindow::*)(), MainWindow*, void**)::{lambda()#1}&&) (args=0x7fffffffc310, fn=...)
    at /usr/include/qt6/QtCore/qobjectdefs_impl.h:65
#15 0x0000555555559b2c in QtPrivate::FunctorCall<std::integer_sequence<unsigned long>, QtPrivate::List<>, void, void (MainWindow::*)()>::call(void (MainWindow::*)(), MainWindow*, void**)
    (f=(void (MainWindow::*)(MainWindow * const)) 0x555555558670 <MainWindow::setDefaultDockArrangement()>, o=0x5555559a3040, arg=0x7fffffffc310) at /usr/include/qt6/QtCore/qobjectdefs_impl.h:126
#16 0x00005555555599c8 in QtPrivate::FunctionPointer<void (MainWindow::*)()>::call<QtPrivate::List<>, void>(void (MainWindow::*)(), MainWindow*, void**)
    (f=(void (MainWindow::*)(MainWindow * const)) 0x555555558670 <MainWindow::setDefaultDockArrangeme--Type <RET> for more, q to quit, c to continue without paging--
nt()>, o=0x5555559a3040, arg=0x7fffffffc310) at /usr/include/qt6/QtCore/qobjectdefs_impl.h:174
#17 0x0000555555559849 in QtPrivate::QCallableObject<void (MainWindow::*)(), QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*)
    (which=1, this_=0x555555965740, r=0x5555559a3040, a=0x7fffffffc310, ret=0x0)
    at /usr/include/qt6/QtCore/qobjectdefs_impl.h:545
#18 0x00007ffff6b02bab in ??? () at /usr/lib64/libQt6Core.so.6
#19 0x00007ffff72fccbd in QAction::activate(QAction::ActionEvent) () at /usr/lib64/libQt6Gui.so.6
#20 0x00007ffff7b68d40 in ??? () at /usr/lib64/libQt6Widgets.so.6
#21 0x00007ffff7bda989 in ??? () at /usr/lib64/libQt6Widgets.so.6
#22 0x00007ffff7d7bc88 in QWidget::event(QEvent*) () at /usr/lib64/libQt6Widgets.so.6
#23 0x00007ffff7d68a86 in QApplicationPrivate::notify_helper(QObject*, QEvent*) ()
    at /usr/lib64/libQt6Widgets.so.6
#24 0x00007ffff7d6981d in QApplication::notify(QObject*, QEvent*) ()
    at /usr/lib64/libQt6Widgets.so.6
#25 0x00007ffff6b1b718 in QCoreApplication::notifyInternal2(QObject*, QEvent*) ()
    at /usr/lib64/libQt6Core.so.6
#26 0x00007ffff7d744eb in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool, bool) () at /usr/lib64/libQt6Widgets.so.6
#27 0x00007ffff7d76e21 in ??? () at /usr/lib64/libQt6Widgets.so.6
#28 0x00007ffff7d7de10 in ??? () at /usr/lib64/libQt6Widgets.so.6
#29 0x00007ffff7d68a86 in QApplicationPrivate::notify_helper(QObject*, QEvent*) ()
    at /usr/lib64/libQt6Widgets.so.6
#30 0x00007ffff6b1b718 in QCoreApplication::notifyInternal2(QObject*, QEvent*) ()
    at /usr/lib64/libQt6Core.so.6
#31 0x00007ffff6f88b34 in QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent*) () at /usr/lib64/libQt6Gui.so.6
#32 0x00007ffff6fea424 in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt6Gui.so.6
#33 0x00007ffff35ae50e in ??? () at /usr/lib64/qt6/plugins/platforms/../../../libQt6XcbQpa.so.6
#34 0x00007ffff6129b12 in ??? () at /usr/lib64/libglib-2.0.so.0
#35 0x00007ffff612cf47 in ??? () at /usr/lib64/libglib-2.0.so.0
#36 0x00007ffff612d6f0 in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
--Type <RET> for more, q to quit, c to continue without paging--
#37 0x00007ffff68ccaf3 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
    () at /usr/lib64/libQt6Core.so.6
#38 0x00007ffff6b48de2 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) ()
    at /usr/lib64/libQt6Core.so.6
#39 0x00007ffff6b48f83 in QCoreApplication::exec() () at /usr/lib64/libQt6Core.so.6
#40 0x00005555555579cc in main (argc=1, argv=0x7fffffffd1b8) at /home/tobias/tmp/9/main.cpp:9