frankenstein:~$ gdb glxspheres
GNU gdb (Ubuntu/Linaro 7.3-0ubuntu2) 7.3-2011.08
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Reading symbols from /usr/bin/glxspheres...(no debugging symbols found)...done.
(gdb) run
Starting program: /usr/bin/glxspheres
[Thread debugging using libthread_db enabled]
Polygons in scene: 62464

Program received signal SIGSEGV, Segmentation fault.
0x00000000 in ?? ()
(gdb) bt
#0  0x00000000 in ?? ()
#1  0xb7fd10c0 in ?? () from /usr/lib/i386-linux-gnu/dri/swrast_dri.so
#2  0xb7ebaf5e in ?? () from /usr/lib/i386-linux-gnu/mesa/libGL.so.1
#3  0xb7e98e50 in ?? () from /usr/lib/i386-linux-gnu/mesa/libGL.so.1
#4  0xb7e95cf3 in ?? () from /usr/lib/i386-linux-gnu/mesa/libGL.so.1
#5  0xb7e95e25 in glXGetConfig () from /usr/lib/i386-linux-gnu/mesa/libGL.so.1
#6  0xb7f165e6 in _glXGetConfig (value=0x807cdd4, attrib=5, vis=0x807c770,
    dpy=0x805c558) at /build/buildd/virtualgl-2.3.1/rr/faker-sym.h:116
#7  buildVisAttribTable (dpy=0x805c558, screen=0)
    at /build/buildd/virtualgl-2.3.1/rr/glxvisual.cpp:133
#8  0xb7f17c6b in __vglMatchVisual (dpy=0x805c558, screen=0, depth=24,
    c_class=4, level=0, stereo=0, trans=0)
    at /build/buildd/virtualgl-2.3.1/rr/glxvisual.cpp:358
#9  0xb7ef7a47 in glXChooseVisual (dpy=0x805c558, screen=0,
    attrib_list=0xbffff218) at /build/buildd/virtualgl-2.3.1/rr/faker.cpp:849
#10 0x0804a4e6 in main ()