(gdb) bt
#0  0x00007ffff301c6f0 in _mesa_max_buffer_index () from /usr/lib/xorg/modules/dri/libdricore.so
#1  0x00007ffff301ca3b in _mesa_validate_DrawRangeElements ()
   from /usr/lib/xorg/modules/dri/libdricore.so
#2  0x00007ffff30dc24b in vbo_exec_DrawRangeElements () from /usr/lib/xorg/modules/dri/libdricore.so
#3  0x0000000000574751 in renderbatch(renderstate&, int, geombatch&) ()
#4  0x0000000000574abd in renderbatches(renderstate&, int) ()
#5  0x000000000057661c in rendergeom(float, bool) ()
#6  0x000000000050228a in gl_drawframe(int, int) ()
#7  0x0000000000466252 in main ()