Application: kwin_x11 (5.2.1) Qt Version: 5.4.0 Operating System: Linux 3.19.1-201.fc21.x86_64 x86_64 Distribution: "Fedora release 21 (Twenty One)" -- Information about the crash: - What I was doing when the application crashed: Select the Plasma session from SDDM and login. I am running Fedora 21 using the plasma5 packages from dvraitl/plasma-5 copr repo. The crash can be reproduced every time. -- Backtrace: Application: KWin (kwin_x11), signal: Segmentation fault Using host libthread_db library "/lib64/libthread_db.so.1". 81 T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS) [KCrash Handler] #5 0x00007f016e9b27a0 in xcb_setup_vendor_end () from /lib64/libxcb.so.1 #6 0x00007f016e9b27f9 in xcb_setup_pixmap_formats_iterator () from /lib64/libxcb.so.1 #7 0x00007f016e9b2839 in xcb_setup_roots_iterator () from /lib64/libxcb.so.1 #8 0x00007f0175f55bc8 in KWin::ColorMapper::ColorMapper(QObject*) () from /lib64/libkwin.so.5 #9 0x00007f0175f5dc5d in KWin::Workspace::Workspace(bool) () from /lib64/libkwin.so.5 #10 0x00007f0176356e46 in QtPrivate::QFunctorSlotObject<KWin::ApplicationX11::performStartup()::{lambda()#2}, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) () from /lib64/libkdeinit5_kwin_x11.so #11 0x00007f016ee8345a in QMetaObject::activate(QObject*, int, int, void**) () from /lib64/libQt5Core.so.5 #12 0x00007f016fca9c42 in KSelectionOwner::Private::claimSucceeded() () from /lib64/libKF5WindowSystem.so.5 #13 0x00007f016fcaa4c1 in KSelectionOwner::filterEvent(void*) () from /lib64/libKF5WindowSystem.so.5 #14 0x00007f016ee50ec0 in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () from /lib64/libQt5Core.so.5 #15 0x00007f0157b4c87d in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () from /usr/lib64/qt5/plugins/platforms/libqxcb.so #16 0x00007f0157b4dd7b in QXcbConnection::processXcbEvents() () from /usr/lib64/qt5/plugins/platforms/libqxcb.so #17 0x00007f016ee84c2a in QObject::event(QEvent*) () from /lib64/libQt5Core.so.5 #18 0x00007f016f73cd3c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5 #19 0x00007f016f742330 in QApplication::notify(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5 #20 0x00007f016ee544ab in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib64/libQt5Core.so.5 #21 0x00007f016ee564eb in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /lib64/libQt5Core.so.5 #22 0x00007f016eea8cf2 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #23 0x00007f0157ba252d in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt5/plugins/platforms/libqxcb.so #24 0x00007f016ee51d42 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5 #25 0x00007f016ee597ec in QCoreApplication::exec() () from /lib64/libQt5Core.so.5 #26 0x00007f0176357eab in kdemain () from /lib64/libkdeinit5_kwin_x11.so #27 0x00007f016d8f0fe0 in __libc_start_main (main=0x400bc0 <main>, argc=3, argv=0x7fff66f62e78, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff66f62e68) at libc-start.c:289 #28 0x0000000000400bee in _start () Reported using DrKonqi
Nested X server (xnest, xephyr, ...) or VNC? There're some bugreports on this, also see eg. https://bugreports.qt.io/browse/QTBUG-29978
None of the above, native local X session sitting in front of the machine.
Does kwin_x11 restart automatically (and w/o crashing, oc.)?
No, it just says that it kept crashing and do I want to use a different window manager. I fear that this is connected to the fact that I do not have xrandr enabled on my display - could that be the issue ? KDE 4 works with no problems though.
That would be odd - the crashing xcb code looks for the first root window. You could try to re-enable the xrandr extension, but I assume this would be rather some forwarded error.
I'm pretty sure it's related. QX11Info::connection passes by screen and QScreen is bound to an xrandr screen, so maybe we don't get a connection and thus we get the crash. A backtrace with full debug symbols could help as we would then know that xcb_connection_t* is null. I had seen similar looking crashes during kwin_wayland development the last weeks whenever I hit the code path before having set up the X connection.
Git commit 289ec53350b50cf134a9867a9341419819b0578e by Martin Gräßlin. Committed on 24/03/2015 at 07:54. Pushed by graesslin into branch 'master'. Add basic information about the X server to supportInformation * Vendor name * Vendor release * Protocol version * All Extensions used by KWin (name, present and version) Need for this recognized due to a bug related to no xrandr present. M +14 -0 workspace.cpp http://commits.kde.org/kwin/289ec53350b50cf134a9867a9341419819b0578e
If you are still able to reproduce please provide a backtrace with debug symbols. Overall what we see just doesn't make sense. It should not crash in that code. I rather think that you hit some instabilities due to a bad combination of packages or even ABI issues caused by using packages from an unstable repository.
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Dear Bug Submitter, This bug has been in NEEDSINFO status with no change for at least 30 days. The bug is now closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging Thank you for helping us make KDE software even better for everyone!