--- core dump of the comment #30 --- ubuntu@201108-8941:~/lp1318584-qt$ gdb /usr/lib/x86_64-linux-gnu/qt5/bin/qmlscene --core=core GNU gdb (Ubuntu 7.7-0ubuntu3) 7.7 Copyright (C) 2014 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-linux-gnu". Type "show configuration" for configuration details. For bug reporting instructions, please see: . Find the GDB manual and other documentation resources online at: . For help, type "help". Type "apropos word" to search for commands related to "word"... Reading symbols from /usr/lib/x86_64-linux-gnu/qt5/bin/qmlscene...Reading symbols from /usr/lib/debug/.build-id/5d/4471e44e258195b8860b8205330baa1def8312.debug...done. done. [New LWP 2632] [New LWP 2624] [New LWP 2626] [New LWP 2627] [New LWP 2631] [New LWP 2625] [New LWP 2623] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". warning: the debug information found in "/usr/lib/x86_64-linux-gnu/dri/r200_dri.so" does not match "/usr/lib/x86_64-linux-gnu/dri/i965_dri.so" (CRC mismatch). Core was generated by `/usr/lib/x86_64-linux-gnu/qt5/bin/qmlscene helloworld.qml'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x00007f407c4ff282 in QGLXContext::makeCurrent (this=0x14112d0, surface=0x1535270) at qglxintegration.cpp:335 335 qglxintegration.cpp: No such file or directory. (gdb) thread apply all bt Thread 7 (Thread 0x7f408615b780 (LWP 2623)): #0 pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 #1 0x00007f4083f4d7fa in wait (time=18446744073709551615, this=0x158d5f0) at thread/qwaitcondition_unix.cpp:136 #2 QWaitCondition::wait (this=, mutex=0x15538c0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:208 #3 0x00007f4085b2f3b1 in QSGThreadedRenderLoop::polishAndSync (this=this@entry=0x1589810, w=w@entry=0x12f0810) at scenegraph/qsgthreadedrenderloop.cpp:1112 #4 0x00007f4085b2fee3 in QSGThreadedRenderLoop::handleExposure (this=this@entry=0x1589810, w=w@entry=0x12f0810) at scenegraph/qsgthreadedrenderloop.cpp:944 #5 0x00007f4085b304c3 in QSGThreadedRenderLoop::exposureChanged (this=0x1589810, window=0x158aa40) at scenegraph/qsgthreadedrenderloop.cpp:881 #6 0x00007f4084647a29 in QWindow::event (this=this@entry=0x158aa40, ev=ev@entry=0x7fffbc2702d0) at kernel/qwindow.cpp:1921 #7 0x00007f4085b55553 in QQuickWindow::event (this=0x158aa40, e=0x7fffbc2702d0) at items/qquickwindow.cpp:1292 #8 0x00007f4084ce7c8c in QApplicationPrivate::notify_helper (this=this@entry=0x12936a0, receiver=receiver@entry=0x158aa40, e=e@entry=0x7fffbc2702d0) at kernel/qapplication.cpp:3486 #9 0x00007f4084cece56 in QApplication::notify (this=0x7fffbc2707f0, receiver=0x158aa40, e=0x7fffbc2702d0) at kernel/qapplication.cpp:3236 #10 0x00007f4084121c2d in QCoreApplication::notifyInternal (this=0x7fffbc2707f0, receiver=receiver@entry=0x158aa40, event=event@entry=0x7fffbc2702d0) at kernel/qcoreapplication.cpp:881 #11 0x00007f4084641ea6 in sendSpontaneousEvent (event=0x7fffbc2702d0, receiver=0x158aa40) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:235 #12 QGuiApplicationPrivate::processExposeEvent (e=0x29fd3a0) at kernel/qguiapplication.cpp:2401 #13 0x00007f4084642995 in QGuiApplicationPrivate::processWindowSystemEvent (e=e@entry=0x29fd3a0) at kernel/qguiapplication.cpp:1473 #14 0x00007f408462b858 in QWindowSystemInterface::sendWindowSystemEvents (flags=...) at kernel/qwindowsysteminterface.cpp:575 #15 0x00007f407c5015b0 in userEventSourceDispatch (source=) at eventdispatchers/qeventdispatcher_glib.cpp:78 #16 0x00007f4082811e04 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #17 0x00007f4082812048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #18 0x00007f40828120ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #19 0x00007f408416e98c in QEventDispatcherGlib::processEvents (this=0x1354fe0, flags=...) at kernel/qeventdispatcher_glib.cpp:426 #20 0x00007f408412096b in QEventLoop::exec (this=this@entry=0x7fffbc270580, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212 #21 0x00007f40841270e1 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1134 #22 0x00007f408463a11c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1343 #23 0x00007f4084ce6605 in QApplication::exec () at kernel/qapplication.cpp:2711 #24 0x0000000000404111 in main (argc=2, argv=) at main.cpp:537 Thread 6 (Thread 0x7f406f164700 (LWP 2625)): #0 0x00007f40835d7fbd in poll () at ../sysdeps/unix/syscall-template.S:81 #1 0x00007f4082811fe4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007f40828120ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007f406f3891ad in ?? () from /usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so #4 0x00007f4082836f15 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #5 0x00007f4082d2a182 in start_thread (arg=0x7f406f164700) at pthread_create.c:312 #6 0x00007f40835e530d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 Thread 5 (Thread 0x7f4057fff700 (LWP 2631)): #0 0x00007f40835d7fbd in poll () at ../sysdeps/unix/syscall-template.S:81 #1 0x00007f4082811fe4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007f40828120ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007f408416e98c in QEventDispatcherGlib::processEvents (this=0x7f40500008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:426 #4 0x00007f408412096b in QEventLoop::exec (this=this@entry=0x7f4057ffee50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212 #5 0x00007f4083f4923a in QThread::exec (this=) at thread/qthread.cpp:509 #6 0x00007f4083f4d233 in QThreadPrivate::start (arg=0x146f2f0) at thread/qthread_unix.cpp:345 #7 0x00007f4082d2a182 in start_thread (arg=0x7f4057fff700) at pthread_create.c:312 #8 0x00007f40835e530d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 Thread 4 (Thread 0x7f406daf2700 (LWP 2627)): #0 0x00007f40835d7fbd in poll () at ../sysdeps/unix/syscall-template.S:81 #1 0x00007f4082811fe4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007f40828120ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007f4082812129 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #4 0x00007f4082836f15 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #5 0x00007f4082d2a182 in start_thread (arg=0x7f406daf2700) at pthread_create.c:312 ---Type to continue, or q to quit--- #6 0x00007f40835e530d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 Thread 3 (Thread 0x7f406e758700 (LWP 2626)): #0 0x00007f40835d7fbd in poll () at ../sysdeps/unix/syscall-template.S:81 #1 0x00007f4082811fe4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007f408281230a in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007f4073156e16 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0 #4 0x00007f4082836f15 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #5 0x00007f4082d2a182 in start_thread (arg=0x7f406e758700) at pthread_create.c:312 #6 0x00007f40835e530d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 Thread 2 (Thread 0x7f40796ac700 (LWP 2624)): #0 0x00007f40835d7fbd in poll () at ../sysdeps/unix/syscall-template.S:81 #1 0x00007f407f9dbb72 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1 #2 0x00007f407f9dd64f in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1 #3 0x00007f407c4e0729 in QXcbEventReader::run (this=0x12ac8c0) at qxcbconnection.cpp:1018 #4 0x00007f4083f4d233 in QThreadPrivate::start (arg=0x12ac8c0) at thread/qthread_unix.cpp:345 #5 0x00007f4082d2a182 in start_thread (arg=0x7f40796ac700) at pthread_create.c:312 #6 0x00007f40835e530d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 Thread 1 (Thread 0x7f4055dbf700 (LWP 2632)): #0 0x00007f407c4ff282 in QGLXContext::makeCurrent (this=0x14112d0, surface=0x1535270) at qglxintegration.cpp:335 #1 0x00007f4084672b10 in QOpenGLContext::makeCurrent (this=0x1561ce0, surface=0x158aa50) at kernel/qopenglcontext.cpp:772 #2 0x00007f4085b2e2e1 in QSGRenderThread::sync (this=this@entry=0x1553880) at scenegraph/qsgthreadedrenderloop.cpp:515 #3 0x00007f4085b2e4e8 in QSGRenderThread::syncAndRender (this=this@entry=0x1553880) at scenegraph/qsgthreadedrenderloop.cpp:561 #4 0x00007f4085b2ec08 in QSGRenderThread::run (this=0x1553880) at scenegraph/qsgthreadedrenderloop.cpp:666 #5 0x00007f4083f4d233 in QThreadPrivate::start (arg=0x1553880) at thread/qthread_unix.cpp:345 #6 0x00007f4082d2a182 in start_thread (arg=0x7f4055dbf700) at pthread_create.c:312 #7 0x00007f40835e530d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 (gdb) quit