For completeness sake, here's mine on Latitude D630 (Intel 965GM graphics), also inside qglxintegration.cpp but slightly different.

Program received signal SIGSEGV, Segmentation fault.
0x00007fffee0aa81c in QGLXContext::swapBuffers (this=0x81d790, 
    surface=0x638450) at qglxintegration.cpp:392
(gdb) bt
#0  0x00007fffee0aa81c in QGLXContext::swapBuffers (this=0x81d790, 
    surface=0x638450) at qglxintegration.cpp:392
#1  0x00007ffff641cd92 in QOpenGLContext::swapBuffers (this=0x6c6b60, 
    surface=<optimized out>) at kernel/qopenglcontext.cpp:906
#2  0x00007ffff7990a8c in QSGGuiThreadRenderLoop::renderWindow (
    this=this@entry=0xb44110, window=0x7943c0)
    at scenegraph/qsgrenderloop.cpp:381
#3  0x00007ffff7990f1e in QSGGuiThreadRenderLoop::exposureChanged (
    this=0xb44110, window=0x7943c0) at scenegraph/qsgrenderloop.cpp:414
#4  0x00007ffff63e4769 in QWindow::event (this=this@entry=0x7943c0, 
    ev=ev@entry=0x7fffffffd8a0) at kernel/qwindow.cpp:1956
#5  0x00007ffff79bad73 in QQuickWindow::event (this=0x7943c0, e=0x7fffffffd8a0)
    at items/qquickwindow.cpp:1339
#6  0x00007ffff6b3a6dc in QApplicationPrivate::notify_helper (
    this=this@entry=0x616560, receiver=receiver@entry=0x7943c0, 
    e=e@entry=0x7fffffffd8a0) at kernel/qapplication.cpp:3504
#7  0x00007ffff6b3f456 in QApplication::notify (this=0x7fffffffddc0, 
    receiver=0x7943c0, e=0x7fffffffd8a0) at kernel/qapplication.cpp:3287
#8  0x00007ffff5e999d5 in QCoreApplication::notifyInternal (this=
    0x7fffffffddc0, receiver=receiver@entry=0x7943c0, 
    event=event@entry=0x7fffffffd8a0) at kernel/qcoreapplication.cpp:935
#9  0x00007ffff63ddee6 in sendSpontaneousEvent (event=0x7fffffffd8a0, 
    receiver=0x7943c0)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:240
#10 QGuiApplicationPrivate::processExposeEvent (e=0x62f080)
    at kernel/qguiapplication.cpp:2528
#11 0x00007ffff63dea45 in QGuiApplicationPrivate::processWindowSystemEvent (
    e=e@entry=0x62f080) at kernel/qguiapplication.cpp:1566
#12 0x00007ffff63c54d8 in QWindowSystemInterface::sendWindowSystemEvents (
    flags=...) at kernel/qwindowsysteminterface.cpp:579
#13 0x00007fffee0ad000 in userEventSourceDispatch (source=<optimized out>)
    at eventdispatchers/qeventdispatcher_glib.cpp:78
#14 0x00007ffff4512de4 in g_main_context_dispatch ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007ffff4513028 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#16 0x00007ffff45130cc in g_main_context_iteration ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#17 0x00007ffff5ef06bc in QEventDispatcherGlib::processEvents (this=0x6ece20, 
    flags=...) at kernel/qeventdispatcher_glib.cpp:426
#18 0x00007ffff5e978eb in QEventLoop::exec (this=this@entry=0x7fffffffdb60, 
    flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#19 0x00007ffff5e9ef46 in QCoreApplication::exec ()
    at kernel/qcoreapplication.cpp:1188
#20 0x00007ffff63d60cc in QGuiApplication::exec ()
    at kernel/qguiapplication.cpp:1436
#21 0x00007ffff6b38e05 in QApplication::exec () at kernel/qapplication.cpp:2749
#22 0x0000000000404301 in main (argc=2, argv=<optimized out>) at main.cpp:548

I also added one more patch to the qt5-beta1 PPA's qtbase: https://qt.gitorious.org/qt/qtbase/commit/075c36e39beedb33ec4b239d57075f54acb21acf

Since Maarten experienced a trace that also concerned qtdeclarative (Qt Quick), it's worth mentioning there's an updated 5.3 branch snapshot build of qtdeclarative (made compatible with 5.3.0) soon finished building at: https://launchpad.net/~canonical-qt5-edgers/+archive/ubuntu/qt5-proper