Application: systemsettings5 (5.8.5)

Qt Version: 5.7.1
Frameworks Version: 5.31.0
Operating System: Linux 4.4.0-65-generic x86_64
Distribution: KDE neon LTS User Edition 5.8

-- Information about the crash:
- What I was doing when the application crashed:

- Modify GTK appearance settings.
- Modify window decoration.
- Modify workspace theming.

The crash can be reproduced sometimes.

-- Backtrace:
Application: Preferencias del sistema (systemsettings5), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f1f9fe3a8c0 (LWP 2079))]

Thread 6 (Thread 0x7f1f5e879700 (LWP 2089)):
#0  0x00007f1f9c569b5d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1f976a438c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f1f976a449c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f1f9ce8975b in QEventDispatcherGlib::processEvents (this=0x7f1f540008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f1f9ce340ba in QEventLoop::exec (this=this@entry=0x7f1f5e878d00, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#5  0x00007f1f9cc63f64 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:507
#6  0x00007f1f9cc68b48 in QThreadPrivate::start (arg=0x1be8a20) at thread/qthread_unix.cpp:368
#7  0x00007f1f9977a6ba in start_thread (arg=0x7f1f5e879700) at pthread_create.c:333
#8  0x00007f1f9c57582d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7f1f6cfd2700 (LWP 2086)):
#0  0x00007f1f9c569b5d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1f976a438c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f1f976a449c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f1f9ce8975b in QEventDispatcherGlib::processEvents (this=0x7f1f640008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f1f9ce340ba in QEventLoop::exec (this=this@entry=0x7f1f6cfd1d00, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#5  0x00007f1f9cc63f64 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:507
#6  0x00007f1f9cc68b48 in QThreadPrivate::start (arg=0x1cd3960) at thread/qthread_unix.cpp:368
#7  0x00007f1f9977a6ba in start_thread (arg=0x7f1f6cfd2700) at pthread_create.c:333
#8  0x00007f1f9c57582d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f1f6f7fe700 (LWP 2085)):
#0  0x00007f1f976e8a94 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f1f976a3f2a in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f1f976a43f0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f1f976a449c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f1f9ce8975b in QEventDispatcherGlib::processEvents (this=0x7f1f600008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#5  0x00007f1f9ce340ba in QEventLoop::exec (this=this@entry=0x7f1f6f7fdce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#6  0x00007f1f9cc63f64 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:507
#7  0x00007f1f9b5c0bf5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f1f9cc68b48 in QThreadPrivate::start (arg=0x18f44b0) at thread/qthread_unix.cpp:368
#9  0x00007f1f9977a6ba in start_thread (arg=0x7f1f6f7fe700) at pthread_create.c:333
#10 0x00007f1f9c57582d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f1f868ca700 (LWP 2081)):
#0  0x00007f1f9c569b5d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1f976a438c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f1f976a449c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f1f9ce8975b in QEventDispatcherGlib::processEvents (this=0x7f1f800008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007f1f9ce340ba in QEventLoop::exec (this=this@entry=0x7f1f868c9cd0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#5  0x00007f1f9cc63f64 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:507
#6  0x00007f1f9ff8d735 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#7  0x00007f1f9cc68b48 in QThreadPrivate::start (arg=0x7f1fa0001d60) at thread/qthread_unix.cpp:368
#8  0x00007f1f9977a6ba in start_thread (arg=0x7f1f868ca700) at pthread_create.c:333
#9  0x00007f1f9c57582d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f1f8f52e700 (LWP 2080)):
#0  0x00007f1f9c569b5d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1f99ff0c62 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f1f99ff28d7 in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f1f920b7d79 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007f1f9cc68b48 in QThreadPrivate::start (arg=0x773800) at thread/qthread_unix.cpp:368
#5  0x00007f1f9977a6ba in start_thread (arg=0x7f1f8f52e700) at pthread_create.c:333
#6  0x00007f1f9c57582d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f1f9fe3a8c0 (LWP 2079)):
[KCrash Handler]
#6  0x00007f1f9ce3ead7 in QMetaObject::cast (this=0x7f1f9e7e4e60 <QAction::staticMetaObject>, obj=obj@entry=0x1116030) at kernel/qmetaobject.cpp:366
#7  0x00007f1f9ce3eb15 in QMetaObject::cast (this=<optimized out>, obj=obj@entry=0x1116030) at kernel/qmetaobject.cpp:355
#8  0x00007f1f9f6fc03f in qobject_cast<QAction*> (object=0x1116030) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobject.h:495
#9  KActionConflictDetector::eventFilter (this=0x7a7090, watched=0x1116030, event=0x11148f0) at /workspace/build/src/kactionconflictdetector.cpp:44
#10 0x00007f1f9ce35d0c in QCoreApplicationPrivate::sendThroughApplicationEventFilters (this=this@entry=0x755be0, receiver=receiver@entry=0x1116030, event=event@entry=0x11148f0) at kernel/qcoreapplication.cpp:1081
#11 0x00007f1f9e30ff08 in QApplicationPrivate::notify_helper (this=0x755be0, receiver=0x1116030, e=0x11148f0) at kernel/qapplication.cpp:3774
#12 0x00007f1f9e3178c6 in QApplication::notify (this=0x7ffd4ec92fd0, receiver=0x1116030, e=0x11148f0) at kernel/qapplication.cpp:3556
#13 0x00007f1f9ce360c8 in QCoreApplication::notifyInternal2 (receiver=0x1116030, event=event@entry=0x11148f0) at kernel/qcoreapplication.cpp:988
#14 0x00007f1f9ce3878b in QCoreApplication::sendEvent (event=0x11148f0, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#15 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x755060) at kernel/qcoreapplication.cpp:1649
#16 0x00007f1f9ce38bf8 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1503
#17 0x00007f1f9ce89333 in postEventSourceDispatch (s=0x7a2fd0) at kernel/qeventdispatcher_glib.cpp:276
#18 0x00007f1f976a4197 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007f1f976a43f0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007f1f976a449c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007f1f9ce8973f in QEventDispatcherGlib::processEvents (this=0x7acc10, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#22 0x00007f1f9ce340ba in QEventLoop::exec (this=this@entry=0x7ffd4ec92eb0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#23 0x00007f1f9ce3c6cc in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1261
#24 0x000000000040c110 in main (argc=1, argv=<optimized out>) at /workspace/build/app/main.cpp:56

Reported using DrKonqi