kwin backtrace

Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f00ec765840 (LWP 2733))]

Thread 6 (Thread 0x7f00ca0e4700 (LWP 2743)):
#0  0x00007f00eba02428 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /usr/lib/libpthread.so.0
#1  0x00007f00e9d08c66 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQt5Core.so.5
#2  0x00007f00e9d04723 in ?? () from /usr/lib/libQt5Core.so.5
#3  0x00007f00e9d07a9e in ?? () from /usr/lib/libQt5Core.so.5
#4  0x00007f00eb9fc4a4 in start_thread () from /usr/lib/libpthread.so.0
#5  0x00007f00ec19612d in clone () from /usr/lib/libc.so.6

Thread 5 (Thread 0x7f00c941c700 (LWP 2747)):
#0  0x00007f00ec18ee23 in select () from /usr/lib/libc.so.6
#1  0x00007f00e9f3a91f in qt_safe_select(int, fd_set*, fd_set*, fd_set*, timespec const*) () from /usr/lib/libQt5Core.so.5
#2  0x00007f00e9f3c3f7 in QEventDispatcherUNIXPrivate::doSelect(QFlags<QEventLoop::ProcessEventsFlag>, timespec*) () from /usr/lib/libQt5Core.so.5
#3  0x00007f00e9f3c8fe in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#4  0x00007f00e9ee626a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#5  0x00007f00e9d02af4 in QThread::exec() () from /usr/lib/libQt5Core.so.5
#6  0x00007f00e41bd335 in ?? () from /usr/lib/libQt5Qml.so.5
#7  0x00007f00e9d07a9e in ?? () from /usr/lib/libQt5Core.so.5
#8  0x00007f00eb9fc4a4 in start_thread () from /usr/lib/libpthread.so.0
#9  0x00007f00ec19612d in clone () from /usr/lib/libc.so.6

Thread 4 (Thread 0x7f00c3dfa700 (LWP 2752)):
#0  0x00007f00eba02428 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /usr/lib/libpthread.so.0
#1  0x00007f00e9d08c66 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQt5Core.so.5
#2  0x00007f00e9d04723 in ?? () from /usr/lib/libQt5Core.so.5
#3  0x00007f00e9d07a9e in ?? () from /usr/lib/libQt5Core.so.5
#4  0x00007f00eb9fc4a4 in start_thread () from /usr/lib/libpthread.so.0
#5  0x00007f00ec19612d in clone () from /usr/lib/libc.so.6

Thread 3 (Thread 0x7f00c349c700 (LWP 2753)):
#0  0x00007f00eba0207f in pthread_cond_wait@@GLIBC_2.3.2 () from /usr/lib/libpthread.so.0
#1  0x00007f00e8c44564 in ?? () from /usr/lib/libQt5Script.so.5
#2  0x00007f00e8c445a9 in ?? () from /usr/lib/libQt5Script.so.5
#3  0x00007f00eb9fc4a4 in start_thread () from /usr/lib/libpthread.so.0
#4  0x00007f00ec19612d in clone () from /usr/lib/libc.so.6

Thread 2 (Thread 0x7f0036364700 (LWP 2974)):
#0  0x00007f00ec18ee23 in select () from /usr/lib/libc.so.6
#1  0x00007f00e9f3a91f in qt_safe_select(int, fd_set*, fd_set*, fd_set*, timespec const*) () from /usr/lib/libQt5Core.so.5
#2  0x00007f00e9f3c3f7 in QEventDispatcherUNIXPrivate::doSelect(QFlags<QEventLoop::ProcessEventsFlag>, timespec*) () from /usr/lib/libQt5Core.so.5
#3  0x00007f00e9f3c8fe in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#4  0x00007f00e9ee626a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#5  0x00007f00e9d02af4 in QThread::exec() () from /usr/lib/libQt5Core.so.5
#6  0x00007f00e41bd335 in ?? () from /usr/lib/libQt5Qml.so.5
#7  0x00007f00e9d07a9e in ?? () from /usr/lib/libQt5Core.so.5
#8  0x00007f00eb9fc4a4 in start_thread () from /usr/lib/libpthread.so.0
#9  0x00007f00ec19612d in clone () from /usr/lib/libc.so.6

Thread 1 (Thread 0x7f00ec765840 (LWP 2733)):
[KCrash Handler]
#5  0x00007f00e411453a in QV4::Heap::String::append(QV4::Heap::String const*, QChar*) () from /usr/lib/libQt5Qml.so.5
#6  0x00007f00e4114615 in QV4::Heap::String::simplifyString() const () from /usr/lib/libQt5Qml.so.5
#7  0x00007f00e40cf818 in ?? () from /usr/lib/libQt5Qml.so.5
#8  0x00007f00e4076973 in QV4::ExecutionEngine::newStringObject(QV4::Value const&) () from /usr/lib/libQt5Qml.so.5
#9  0x00007f00e410f922 in QV4::Runtime::getProperty(QV4::ExecutionEngine*, QV4::Value const&, int) () from /usr/lib/libQt5Qml.so.5
#10 0x00007f00eb364b39 in ?? ()
#11 0x00007f00e4ad4fc2 in QQuickItem::staticMetaObject () from /usr/lib/libQt5Quick.so.5
#12 0x00007f002cea6260 in ?? ()
#13 0x0000000003c6cfb0 in ?? ()
#14 0x00007f002cea6258 in ?? ()
#15 0x0000000002771190 in ?? ()
#16 0x00007f00ea46d7f9 in ?? () from /usr/lib/libQt5Gui.so.5
#17 0x0000000002771190 in ?? ()
#18 0x0000000002771190 in ?? ()
#19 0x0000000003c69ff8 in ?? ()
#20 0x0000000000000003 in ?? ()
#21 0x0000000003c71500 in ?? ()
#22 0x00007f00e44fe300 in ?? () from /usr/lib/libQt5Qml.so.5
#23 0x00007f002cea61f8 in ?? ()
#24 0x0000000002771190 in ?? ()
#25 0x00007ffddd2df4f0 in ?? ()
#26 0x00007f00c82136b0 in ?? ()
#27 0x0000000000000000 in ?? ()