#0  0xffffffff in vtable for QPushButton () at /appl/Qt/Qt-5.6.0-pre/lib/libQt5Widgets.so.5
#1  0xffffffff in QMetaObject::cast(QObject*) const (this=0xb7fcf3f4 <QWidgetWindow::staticMetaObject>, obj=obj@entry=0x8093018)
    at /home/user/devel/qt5/qtbase/src/corelib/kernel/qmetaobject.cpp:331
#2  0xffffffff in QApplicationPrivate::isWindowBlocked(QWindow*, QWindow**) const (object=0x8093018) at ../../include/QtCore/../../../../qt5/qtbase/src/corelib/kernel/qobject.h:518
#3  0xffffffff in QApplicationPrivate::isWindowBlocked(QWindow*, QWindow**) const (this=0x8057498, window=0x8261c50, blockingWindow=0xbfffe33c)
    at /home/user/devel/qt5/qtbase/src/widgets/kernel/qapplication.cpp:2533
#4  0xffffffff in QXcbWindow::relayFocusToModalWindow() const (this=this@entry=0x817f930) at /home/user/devel/qt5/qtbase/src/plugins/platforms/xcb/qxcbwindow.cpp:871
#5  0xffffffff in QXcbWindow::doFocusIn() (this=0x817f930) at /home/user/devel/qt5/qtbase/src/plugins/platforms/xcb/qxcbwindow.cpp:882
#6  0xffffffff in QXcbWindow::handleFocusInEvent(xcb_focus_in_event_t const*) (this=0x817f930) at /home/user/devel/qt5/qtbase/src/plugins/platforms/xcb/qxcbwindow.cpp:2373
#7  0xffffffff in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) (this=this@entry=0x8066280, event=event@entry=0x822f038)
    at /home/user/devel/qt5/qtbase/src/plugins/platforms/xcb/qxcbconnection.cpp:1141
#8  0xffffffff in QXcbConnection::processXcbEvents() (this=0x8066280) at /home/user/devel/qt5/qtbase/src/plugins/platforms/xcb/qxcbconnection.cpp:1701
#9  0xffffffff in QXcbConnection::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (_o=<optimized out>, _id=<optimized out>, _a=<optimized out>, _c=<optimized out>)
    at .moc/moc_qxcbconnection.cpp:187
#10 0xffffffff in QMetaCallEvent::placeMetaCall(QObject*) (this=0xb3f03610, object=0x8066280) at /home/user/devel/qt5/qtbase/src/corelib/kernel/qobject.cpp:495
#11 0xffffffff in QObject::event(QEvent*) (this=this@entry=0x8066280, e=e@entry=0xb3f03610) at /home/user/devel/qt5/qtbase/src/corelib/kernel/qobject.cpp:1256
#12 0xffffffff in QXcbConnection::event(QEvent*) (this=0x8066280, e=0xb3f03610) at /home/user/devel/qt5/qtbase/src/plugins/platforms/xcb/qxcbconnection.cpp:2312
#13 0xffffffff in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=0x8057498, receiver=0x8066280, e=0xb3f03610)
    at /home/user/devel/qt5/qtbase/src/widgets/kernel/qapplication.cpp:3712
#14 0xffffffff in QApplication::notify(QObject*, QEvent*) (this=0xbfffeb38, receiver=0x8066280, e=0xb3f03610) at /home/user/devel/qt5/qtbase/src/widgets/kernel/qapplication.cpp:3493
#15 0xffffffff in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=receiver@entry=0x8066280, event=event@entry=0xb3f03610)
    at /home/user/devel/qt5/qtbase/src/corelib/kernel/qcoreapplication.cpp:1013
#16 0xffffffff in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (event=0xb3f03610, receiver=0x8066280)
    at ../../include/QtCore/../../../../qt5/qtbase/src/corelib/kernel/qcoreapplication.h:227
#17 0xffffffff in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x8057090)
    at /home/user/devel/qt5/qtbase/src/corelib/kernel/qcoreapplication.cpp:1648
#18 0xffffffff in QCoreApplication::sendPostedEvents(QObject*, int) (receiver=receiver@entry=0x0, event_type=event_type@entry=0)
    at /home/user/devel/qt5/qtbase/src/corelib/kernel/qcoreapplication.cpp:1506
#19 0xffffffff in postEventSourceDispatch(GSource*, GSourceFunc, gpointer) (s=s@entry=0x8086618) at /home/user/devel/qt5/qtbase/src/corelib/kernel/qeventdispatcher_glib.cpp:270
#20 0xffffffff in g_main_context_dispatch (context=0xb3f02a00, context@entry=0x8086618) at gmain.c:3111
#21 0xffffffff in g_main_context_dispatch (context=context@entry=0xb3f02a00) at gmain.c:3710
#22 0xffffffff in g_main_context_iterate (context=context@entry=0xb3f02a00, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3781
#23 0xffffffff in g_main_context_iteration (context=0xb3f02a00, may_block=1) at gmain.c:3842
#24 0xffffffff in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x80864f0, flags=flags@entry=...)
    at /home/user/devel/qt5/qtbase/src/corelib/kernel/qeventdispatcher_glib.cpp:417
#25 0xffffffff in QPAEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x80864f0, flags=...)
    at /home/user/devel/qt5/qtbase/src/platformsupport/eventdispatchers/qeventdispatcher_glib.cpp:115
#26 0xffffffff in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0xbfffea50, flags=flags@entry=...)
    at /home/user/devel/qt5/qtbase/src/corelib/kernel/qeventloop.cpp:128
#27 0xffffffff in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0xbfffea50, flags=flags@entry=...)
    at /home/user/devel/qt5/qtbase/src/corelib/kernel/qeventloop.cpp:204
#28 0xffffffff in QCoreApplication::exec() () at /home/user/devel/qt5/qtbase/src/corelib/kernel/qcoreapplication.cpp:1283
#29 0xffffffff in QGuiApplication::exec() () at /home/user/devel/qt5/qtbase/src/gui/kernel/qguiapplication.cpp:1593
#30 0xffffffff in QApplication::exec() () at /home/user/devel/qt5/qtbase/src/widgets/kernel/qapplication.cpp:2971
#31 0x0804b156 in main(int, char**) (argc=1, argv=0xbfffebe4) at ../StartupCrash/main.cc:35