Application: systemsettings5 (5.12.4)

Qt Version: 5.9.4
Frameworks Version: 5.44.0
Operating System: Linux 4.15.14-300.fc27.x86_64 x86_64
Distribution (Platform): Fedora RPMs

-- Information about the crash:
I was messing with chaning and trying different task switchers for a few minutes, and also made use of the preview task switcher function that displays a dummy. Somehow the preview got stuck on screen, I closed System Settings and it still remained on screen above everything else including the actual task switcher, reopened System Settings and it immediately crashed but the preview was now gone.

-- Backtrace:
Application: System Settings (systemsettings5), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f2b93c5c540 (LWP 3610))]

Thread 3 (Thread 0x7f2b6fe28700 (LWP 3612)):
#0  0x00007f2b85a9f3f4 in g_mutex_unlock () from /lib64/libglib-2.0.so.0
#1  0x00007f2b85a59399 in g_main_context_prepare () from /lib64/libglib-2.0.so.0
#2  0x00007f2b85a59dcb in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#3  0x00007f2b85a59fac in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#4  0x00007f2b8e95bc4b in QEventDispatcherGlib::processEvents (this=0x7f2b68000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#5  0x00007f2b8e90996a in QEventLoop::exec (this=this@entry=0x7f2b6fe27ca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#6  0x00007f2b8e75a8ca in QThread::exec (this=this@entry=0x7f2b903d6060 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread.cpp:515
#7  0x00007f2b90162449 in QDBusConnectionManager::run (this=0x7f2b903d6060 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:178
#8  0x00007f2b8e75ede2 in QThreadPrivate::start (arg=0x7f2b903d6060 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:368
#9  0x00007f2b8a5bc50b in start_thread () from /lib64/libpthread.so.0
#10 0x00007f2b8db1016f in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7f2b7971c700 (LWP 3611)):
#0  0x00007f2b8db05c6b in poll () from /lib64/libc.so.6
#1  0x00007f2b8942cfe7 in _xcb_conn_wait () from /lib64/libxcb.so.1
#2  0x00007f2b8942edda in xcb_wait_for_event () from /lib64/libxcb.so.1
#3  0x00007f2b7c2babf9 in QXcbEventReader::run (this=0x55e868423000) at qxcbconnection.cpp:1335
#4  0x00007f2b8e75ede2 in QThreadPrivate::start (arg=0x55e868423000) at thread/qthread_unix.cpp:368
#5  0x00007f2b8a5bc50b in start_thread () from /lib64/libpthread.so.0
#6  0x00007f2b8db1016f in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7f2b93c5c540 (LWP 3610)):
[KCrash Handler]
#6  QWidgetPrivate::createTLExtra (this=0x55e86873f9e0) at kernel/qwidget.cpp:1762
#7  0x00007f2b8f83c568 in QWidget::setAttribute (this=0x55e86847d600, attribute=<optimized out>, on=true) at kernel/qwidget.cpp:11300
#8  0x00007f2b8f83d930 in QWidget::winId (this=0x55e86847d600) at kernel/qwidget.cpp:2551
#9  0x000055e86726a08a in SystemSettingsApp::<lambda()>::operator() (__closure=<optimized out>) at /usr/src/debug/plasma-systemsettings-5.12.4-1.fc27.x86_64/app/SystemSettingsApp.cpp:31
#10 QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, SystemSettingsApp::SystemSettingsApp(int&, char**)::<lambda()> >::call (arg=<optimized out>, f=...) at /usr/include/qt5/QtCore/qobjectdefs_impl.h:130
#11 QtPrivate::Functor<SystemSettingsApp::SystemSettingsApp(int&, char**)::<lambda()>, 0>::call<QtPrivate::List<>, void> (arg=<optimized out>, f=...) at /usr/include/qt5/QtCore/qobjectdefs_impl.h:240
#12 QtPrivate::QFunctorSlotObject<SystemSettingsApp::SystemSettingsApp(int&, char**)::<lambda()>, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase *, QObject *, void **, bool *) (which=<optimized out>, this_=<optimized out>, r=<optimized out>, a=<optimized out>, ret=<optimized out>) at /usr/include/qt5/QtCore/qobject_impl.h:168
#13 0x00007f2b8e933637 in QtPrivate::QSlotObjectBase::call (a=0x7fff074957a0, r=0x7fff07496140, this=0x55e868475540) at ../../include/QtCore/../../src/corelib/kernel/qobject_impl.h:101
#14 QMetaObject::activate (sender=sender@entry=0x55e86845d580, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fff074957a0) at kernel/qobject.cpp:3749
#15 0x00007f2b8e933b87 in QMetaObject::activate (sender=sender@entry=0x55e86845d580, m=m@entry=0x7f2b90cc06e0 <KDBusService::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fff074957a0) at kernel/qobject.cpp:3628
#16 0x00007f2b90abac37 in KDBusService::activateRequested (this=this@entry=0x55e86845d580, _t1=..., _t2=...) at /usr/src/debug/kf5-kdbusaddons-5.44.0-1.fc27.x86_64/x86_64-redhat-linux-gnu/src/KF5DBusAddons_autogen/EWIEGA46WW/moc_kdbusservice.cpp:196
#17 0x00007f2b90ab54dc in KDBusService::Activate (this=0x55e86845d580, platform_data=...) at /usr/src/debug/kf5-kdbusaddons-5.44.0-1.fc27.x86_64/src/kdbusservice.cpp:204
#18 0x00007f2b90abaa05 in KDBusServiceAdaptor::qt_metacall (this=0x55e868462100, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0x7fff07495910) at /usr/src/debug/kf5-kdbusaddons-5.44.0-1.fc27.x86_64/x86_64-redhat-linux-gnu/src/kdbusservice_adaptor.moc:140
#19 0x00007f2b9016d8b8 in QDBusConnectionPrivate::deliverCall (this=this@entry=0x7f2b68004e80, object=object@entry=0x55e868462100, msg=..., metaTypes=..., slotIdx=<optimized out>) at qdbusintegrator.cpp:998
#20 0x00007f2b90172900 in QDBusConnectionPrivate::activateCall (this=this@entry=0x7f2b68004e80, object=0x55e868462100, flags=flags@entry=273, msg=...) at qdbusintegrator.cpp:901
#21 0x00007f2b901731cc in QDBusConnectionPrivate::activateCall (msg=..., flags=273, object=<optimized out>, this=0x7f2b68004e80) at qdbusintegrator.cpp:850
#22 QDBusConnectionPrivate::activateObject (this=0x7f2b68004e80, node=..., msg=..., pathStartPos=<optimized out>) at qdbusintegrator.cpp:1491
#23 0x00007f2b9017597e in QDBusActivateObjectEvent::placeMetaCall (this=0x55e868ba6630) at qdbusintegrator.cpp:1611
#24 0x00007f2b8e93426a in QObject::event (this=0x55e86845d580, e=<optimized out>) at kernel/qobject.cpp:1246
#25 0x00007f2b8f80b92c in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x55e86845d580, e=0x55e868ba6630) at kernel/qapplication.cpp:3722
#26 0x00007f2b8f813174 in QApplication::notify (this=0x7fff07496140, receiver=0x55e86845d580, e=0x55e868ba6630) at kernel/qapplication.cpp:3481
#27 0x00007f2b8e90abe7 in QCoreApplication::notifyInternal2 (receiver=0x55e86845d580, event=event@entry=0x55e868ba6630) at kernel/qcoreapplication.cpp:1016
#28 0x00007f2b8e90d36b in QCoreApplication::sendEvent (event=0x55e868ba6630, receiver=<optimized out>) at kernel/qcoreapplication.h:233
#29 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x55e868409510) at kernel/qcoreapplication.cpp:1676
#30 0x00007f2b8e90d888 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1530
#31 0x00007f2b8e95be43 in postEventSourceDispatch (s=0x55e8684678d0) at kernel/qeventdispatcher_glib.cpp:276
#32 0x00007f2b85a59b77 in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#33 0x00007f2b85a59f20 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#34 0x00007f2b85a59fac in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#35 0x00007f2b8e95bc2f in QEventDispatcherGlib::processEvents (this=0x55e86846b7b0, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#36 0x00007f2b8e90996a in QEventLoop::exec (this=this@entry=0x7fff07496060, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#37 0x00007f2b8e912094 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1289
#38 0x000055e867269f04 in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/plasma-systemsettings-5.12.4-1.fc27.x86_64/app/main.cpp:67

Reported using DrKonqi