Application: kwin_x11 (5.16.2)

Qt Version: 5.12.2
Frameworks Version: 5.59.0
Operating System: FreeBSD 12.0-CURRENT amd64
Distribution (Platform): FreeBSD Ports

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

I switched to my X / KDE session from another session (using Ctrl+Alt+F9).

The crash can be reproduced sometimes.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
[KCrash Handler]
#6  0x000000080c359b5a in thr_kill () at thr_kill.S:3
#7  0x000000080c359b24 in __raise (s=6) at /usr/src/lib/libc/gen/raise.c:52
#8  0x000000080c359a99 in abort () at /usr/src/lib/libc/stdlib/abort.c:65
#9  0x000000080b2a46e9 in QMessageLogger::fatal(char const*, ...) const () at /usr/local/lib/qt5/libQt5Core.so.5
#10 0x000000081eb2f9d9 in  () at /usr/local/lib/qt5/plugins/org.kde.kwin.platforms/KWinX11Platform.so
#11 0x000000080b4b5eff in QMetaObject::activate(QObject*, int, int, void**) () at /usr/local/lib/qt5/libQt5Core.so.5
#12 0x000000080b4be7c4 in QTimer::timerEvent(QTimerEvent*) () at /usr/local/lib/qt5/libQt5Core.so.5
#13 0x000000080b4aedd3 in QObject::event(QEvent*) () at /usr/local/lib/qt5/libQt5Core.so.5
#14 0x0000000809f79660 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/local/lib/qt5/libQt5Widgets.so.5
#15 0x0000000809f7ac26 in QApplication::notify(QObject*, QEvent*) () at /usr/local/lib/qt5/libQt5Widgets.so.5
#16 0x000000080b482d80 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/local/lib/qt5/libQt5Core.so.5
#17 0x000000080b4dae2f in QTimerInfoList::activateTimers() () at /usr/local/lib/qt5/libQt5Core.so.5
#18 0x000000080b4d9285 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/local/lib/qt5/libQt5Core.so.5
#19 0x000000080b47e76e in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/local/lib/qt5/libQt5Core.so.5
#20 0x000000080b2abbb9 in QThread::exec() () at /usr/local/lib/qt5/libQt5Core.so.5
#21 0x000000080b2acbb4 in  () at /usr/local/lib/qt5/libQt5Core.so.5
#22 0x000000080c05bc55 in thread_start (curthread=0x809d78900) at /usr/src/lib/libthr/thread/thr_create.c:289
#23 0x0000000000000000 in  ()

Thread 3 (LWP 102936 of process 45924):
#1  0x000000080c05ee0c in __thr_ppoll (pfd=0x819bf6018, nfds=1, timeout=0x0, newsigmask=0x0) at /usr/src/lib/libthr/thread/thr_syscalls.c:356
#2  0x000000080b4d79ff in qt_safe_poll(pollfd*, unsigned int, timespec const*) () at /usr/local/lib/qt5/libQt5Core.so.5
#3  0x000000080b4d918a in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/local/lib/qt5/libQt5Core.so.5
#4  0x000000080b47e76e in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/local/lib/qt5/libQt5Core.so.5
#5  0x000000080b2abbb9 in QThread::exec() () at /usr/local/lib/qt5/libQt5Core.so.5
#6  0x0000000803157179 in  () at /usr/local/lib/qt5/libQt5Qml.so.5
#7  0x000000080b2acbb4 in  () at /usr/local/lib/qt5/libQt5Core.so.5
#8  0x000000080c05bc55 in thread_start (curthread=0x809d3d000) at /usr/src/lib/libthr/thread/thr_create.c:289
#9  0x0000000000000000 in  ()

Thread 2 (LWP 102931 of process 45924):
#1  0x000000080c05ee0c in __thr_ppoll (pfd=0x800b83b18, nfds=1, timeout=0x0, newsigmask=0x0) at /usr/src/lib/libthr/thread/thr_syscalls.c:356
#2  0x000000080b4d79ff in qt_safe_poll(pollfd*, unsigned int, timespec const*) () at /usr/local/lib/qt5/libQt5Core.so.5
#3  0x000000080b4d918a in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/local/lib/qt5/libQt5Core.so.5
#4  0x000000080b47e76e in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/local/lib/qt5/libQt5Core.so.5
#5  0x000000080b2abbb9 in QThread::exec() () at /usr/local/lib/qt5/libQt5Core.so.5
#6  0x0000000808dab243 in  () at /usr/local/lib/qt5/libQt5DBus.so.5
#7  0x000000080b2acbb4 in  () at /usr/local/lib/qt5/libQt5Core.so.5
#8  0x000000080c05bc55 in thread_start (curthread=0x800719700) at /usr/src/lib/libthr/thread/thr_create.c:289
#9  0x0000000000000000 in  ()

Thread 1 (LWP 101889 of process 45924):
#1  0x000000080c05e64c in __thr_nanosleep (time_to_sleep=0x7fffffff9b50, time_remaining=0x7fffffff9b40) at /usr/src/lib/libthr/thread/thr_syscalls.c:287
#2  0x000000080c2e889b in __sleep (seconds=1) at /usr/src/lib/libc/gen/sleep.c:62
#3  0x0000000809554bfa in  () at /usr/local/lib/libKF5Crash.so.5
#4  0x000000080955433a in KCrash::defaultCrashHandler(int) () at /usr/local/lib/libKF5Crash.so.5
#5  0x000000080c0618c6 in handle_signal (actp=0x7fffffffd100, sig=11, info=0x7fffffffd4f0, ucp=0x7fffffffd180) at /usr/src/lib/libthr/thread/thr_sig.c:246
#6  0x000000080c060f0f in thr_sighandler (sig=11, info=0x7fffffffd4f0, _ucp=0x7fffffffd180) at /usr/src/lib/libthr/thread/thr_sig.c:189
#7  0x00007ffffffff003 in <signal handler called> ()
#8  0x0000000825cf7d9a in KWin::SceneOpenGL::createScene(QObject*) () at /usr/local/lib/qt5/plugins/org.kde.kwin.scenes/KWinSceneOpenGL.so
#9  0x0000000825d06c42 in KWin::OpenGLFactory::create(QObject*) const () at /usr/local/lib/qt5/plugins/org.kde.kwin.scenes/KWinSceneOpenGL.so
#10 0x0000000800dbed25 in KWin::Compositor::slotCompositingOptionsInitialized() () at /usr/local/lib/libkwin.so.5
#11 0x000000080b4af021 in QObject::event(QEvent*) () at /usr/local/lib/qt5/libQt5Core.so.5
#12 0x0000000809f79660 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/local/lib/qt5/libQt5Widgets.so.5
#13 0x0000000809f7ac26 in QApplication::notify(QObject*, QEvent*) () at /usr/local/lib/qt5/libQt5Widgets.so.5
#14 0x000000080b482d80 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/local/lib/qt5/libQt5Core.so.5
#15 0x000000080b483dd2 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/local/lib/qt5/libQt5Core.so.5
#16 0x000000080b4d8e68 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/local/lib/qt5/libQt5Core.so.5
#17 0x000000081b8b2ef4 in  () at /usr/local/lib/qt5/libQt5XcbQpa.so.5
#18 0x000000080b47e76e in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/local/lib/qt5/libQt5Core.so.5
#19 0x000000080b48343e in QCoreApplication::exec() () at /usr/local/lib/qt5/libQt5Core.so.5
#20 0x000000080082dbaf in kdemain () at /usr/local/lib/libkdeinit5_kwin_x11.so
#21 0x0000000000400bdf in  ()
#22 0x0000000800625000 in  ()
#23 0x0000000000000000 in  ()
[Inferior 1 (process 45924) detached]

Reported using DrKonqi