Application: systemsettings5 (5.8.6)

Qt Version: 5.6.2
Frameworks Version: 5.26.0
Operating System: Linux 4.10.12-1.g3043bd9-default x86_64
Distribution: "openSUSE Leap 42.3 Alpha"

-- Information about the crash:
- What I was doing when the application crashed:
using 
fontconfig within kdesettings. trying many different variants of force DPI, antialias, subpixel ... forward and backward to get a decent looking KDE display both on the Laptop and on an external monitor
- Custom settings of the application:
nothing special, tried many different

on openSUSE Leap 42.3 alpha

-- Backtrace:
Application: Systemeinstellungen (systemsettings5), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fb2bdb1f780 (LWP 5554))]

Thread 3 (Thread 0x7fb2a5b30700 (LWP 5556)):
#0  0x00007fb2b983b49d in poll () at /lib64/libc.so.6
#1  0x00007fb2b5453314 in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007fb2b545342c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007fb2ba14819b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007fb2ba0f5beb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb2b9f30f5a in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#6  0x00007fb2baa4b295 in  () at /usr/lib64/libQt5DBus.so.5
#7  0x00007fb2b9f35a29 in  () at /usr/lib64/libQt5Core.so.5
#8  0x00007fb2b5970744 in start_thread () at /lib64/libpthread.so.0
#9  0x00007fb2b9843d3d in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7fb2ab0c0700 (LWP 5555)):
#0  0x00007fb2b983b49d in poll () at /lib64/libc.so.6
#1  0x00007fb2b61e63e2 in  () at /usr/lib64/libxcb.so.1
#2  0x00007fb2b61e7fcf in xcb_wait_for_event () at /usr/lib64/libxcb.so.1
#3  0x00007fb2ad61b0d9 in  () at /usr/lib64/libQt5XcbQpa.so.5
#4  0x00007fb2b9f35a29 in  () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb2b5970744 in start_thread () at /lib64/libpthread.so.0
#6  0x00007fb2b9843d3d in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7fb2bdb1f780 (LWP 5554)):
[KCrash Handler]
#6  0x00007fb2a9b58884 in KNotification::flags() const () at /usr/lib64/libKF5Notifications.so.5
#7  0x00007fb2a9b767e7 in  () at /usr/lib64/libKF5Notifications.so.5
#8  0x00007fb2a9b7c265 in  () at /usr/lib64/libKF5Notifications.so.5
#9  0x00007fb2ba1217c1 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib64/libQt5Core.so.5
#10 0x00007fb2a8f21ea5 in  () at /usr/lib64/libphonon4qt5.so.4
#11 0x00007fb2ba122e16 in QObject::event(QEvent*) () at /usr/lib64/libQt5Core.so.5
#12 0x00007fb2bbc6528c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib64/libQt5Widgets.so.5
#13 0x00007fb2bbc698ea in QApplication::notify(QObject*, QEvent*) () at /usr/lib64/libQt5Widgets.so.5
#14 0x00007fb2ba0f7bd5 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib64/libQt5Core.so.5
#15 0x00007fb2ba0f99ba in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib64/libQt5Core.so.5
#16 0x00007fb2ba148af3 in  () at /usr/lib64/libQt5Core.so.5
#17 0x00007fb2b5453134 in g_main_context_dispatch () at /usr/lib64/libglib-2.0.so.0
#18 0x00007fb2b5453388 in  () at /usr/lib64/libglib-2.0.so.0
#19 0x00007fb2b545342c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#20 0x00007fb2ba14817c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#21 0x00007fb2ba0f5beb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#22 0x00007fb2ba0fdad6 in QCoreApplication::exec() () at /usr/lib64/libQt5Core.so.5
#23 0x000000000040ce27 in  ()
#24 0x00007fb2b977a6e5 in __libc_start_main () at /lib64/libc.so.6
#25 0x000000000040ce89 in _start ()

Reported using DrKonqi