Hello I have similar behaviour and I have managed to capture the backtrace from the fault (below). Let me know if I can help with anything else.
Thanks Tim ---- Backtrace ---- Application: KWin (kwin_x11), signal: Segmentation fault Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [Current thread is 1 (Thread 0x7f4bf57d78c0 (LWP 143875))] Thread 4 (Thread 0x7f4beebe8700 (LWP 143888)): #0 futex_abstimed_wait_cancelable (private=0, abstime=0x7f4beebe7c50, clockid=-289506352, expected=0, futex_word=0x55f64fc93484) at ../sysdeps/nptl/futex-internal.h:320 #1 __pthread_cond_wait_common (abstime=0x7f4beebe7c50, clockid=-289506352, mutex=0x55f64fc93430, cond=0x55f64fc93458) at pthread_cond_wait.c:520 #2 __pthread_cond_timedwait (cond=0x55f64fc93458, mutex=0x55f64fc93430, abstime=0x7f4beebe7c50) at pthread_cond_wait.c:656 #3 0x00007f4bfbc52aa4 in QWaitCondition::wait(QMutex*, QDeadlineTimer) () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #4 0x00007f4bfbc50ae1 in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #5 0x00007f4bfbc4cb01 in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #6 0x00007f4bfb06aea7 in start_thread (arg=<optimized out>) at pthread_create.c:477 #7 0x00007f4bfd3ead4f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 3 (Thread 0x7f4beffff700 (LWP 143880)): #0 0x00007f4bfd3e0456 in __ppoll (fds=0x7f4be800d0b8, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:44 #1 0x00007f4bfbe7f779 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #2 0x00007f4bfbe80e13 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #3 0x00007f4bfbe2ab7b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #4 0x00007f4bfbc4b9be in QThread::exec() () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #5 0x00007f4bfa18ba27 in ?? () from /lib/x86_64-linux-gnu/libQt5DBus.so.5 #6 0x00007f4bfbc4cb01 in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #7 0x00007f4bfb06aea7 in start_thread (arg=<optimized out>) at pthread_create.c:477 #8 0x00007f4bfd3ead4f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 2 (Thread 0x7f4bf50d7700 (LWP 143878)): #0 0x00007f4bfd3e035f in __GI___poll (fds=0x7f4bf50d6be8, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29 #1 0x00007f4bfbb62d02 in ?? () from /lib/x86_64-linux-gnu/libxcb.so.1 #2 0x00007f4bfbb6498a in xcb_wait_for_event () from /lib/x86_64-linux-gnu/libxcb.so.1 #3 0x00007f4bf53f4260 in ?? () from /lib/x86_64-linux-gnu/libQt5XcbQpa.so.5 #4 0x00007f4bfbc4cb01 in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #5 0x00007f4bfb06aea7 in start_thread (arg=<optimized out>) at pthread_create.c:477 #6 0x00007f4bfd3ead4f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 1 (Thread 0x7f4bf57d78c0 (LWP 143875)): [KCrash Handler] #4 0x00007f4bfbccdef0 in QString::operator=(QString const&) () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #5 0x00007f4bfd0fd10c in ?? () from /lib/x86_64-linux-gnu/libkwin.so.5 #6 0x00007f4bee034910 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/org.kde.kdecoration2/breezedecoration.so #7 0x00007f4bee0387f9 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/org.kde.kdecoration2/breezedecoration.so #8 0x00007f4bee038a28 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/org.kde.kdecoration2/breezedecoration.so #9 0x00007f4bfd0fed52 in KWin::Decoration::DecorationBridge::createDecoration(KWin::AbstractClient*) () from /lib/x86_64-linux-gnu/libkwin.so.5 #10 0x00007f4bfd0d34cc in KWin::Client::createDecoration(QRect const&) () from /lib/x86_64-linux-gnu/libkwin.so.5 #11 0x00007f4bfd0d7758 in KWin::Client::updateDecoration(bool, bool) () from /lib/x86_64-linux-gnu/libkwin.so.5 #12 0x00007f4bfd16b246 in KWin::Client::manage(unsigned int, bool) () from /lib/x86_64-linux-gnu/libkwin.so.5 #13 0x00007f4bfd2079a5 in KWin::Workspace::createClient(unsigned int, bool) () from /lib/x86_64-linux-gnu/libkwin.so.5 #14 0x00007f4bfd20ba1f in KWin::Workspace::initWithX11() () from /lib/x86_64-linux-gnu/libkwin.so.5 #15 0x00007f4bfd20cd51 in KWin::Workspace::init() () from /lib/x86_64-linux-gnu/libkwin.so.5 #16 0x00007f4bfd20d56d in KWin::Workspace::Workspace(QString const&) () from /lib/x86_64-linux-gnu/libkwin.so.5 #17 0x00007f4bfd168054 in KWin::Application::createWorkspace() () from /lib/x86_64-linux-gnu/libkwin.so.5 #18 0x00007f4bfd4b9e6c in ?? () from /lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so #19 0x00007f4bfbe62796 in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #20 0x00007f4bfd4ba2cc in ?? () from /lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so #21 0x00007f4bfbe62796 in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #22 0x00007f4bfce44633 in ?? () from /lib/x86_64-linux-gnu/libKF5WindowSystem.so.5 #23 0x00007f4bfbe5811f in QObject::event(QEvent*) () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #24 0x00007f4bfc8ee14f in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib/x86_64-linux-gnu/libQt5Widgets.so.5 #25 0x00007f4bfbe2c1ba in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #26 0x00007f4bfbe82ad3 in QTimerInfoList::activateTimers() () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #27 0x00007f4bfbe80f67 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #28 0x00007f4bf53f55fe in ?? () from /lib/x86_64-linux-gnu/libQt5XcbQpa.so.5 #29 0x00007f4bfbe2ab7b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #30 0x00007f4bfbe32df0 in QCoreApplication::exec() () from /lib/x86_64-linux-gnu/libQt5Core.so.5 #31 0x00007f4bfd4bb886 in kdemain () from /lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so #32 0x00007f4bfd313cca in __libc_start_main (main=0x55f64f1b3050, argc=3, argv=0x7fff71ba2d08, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff71ba2cf8) at ../csu/libc-start.c:308 #33 0x000055f64f1b308a in _start () [Inferior 1 (process 143875) detached] ---- End of Backtrace ----
