[16:59][igneous@lamehostname:~]$ gdb /usr/bin/glxinfo 
GNU gdb (GDB) 7.0
Copyright (C) 2009 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/bin/glxinfo...(no debugging symbols found)...done.
(gdb) run
Starting program: /usr/bin/glxinfo 
[Thread debugging using libthread_db enabled]
name of display: :0.0
glxinfo: ../common/drirenderbuffer.c:69: driNewRenderbuffer: Assertion `format == 0x1908 || format == 0x8050 || format == 0x8058 || format == 0x81A5 || format == 0x81A6 || format == 0x81A7 || format == 
0x8D48' failed.

Program received signal SIGABRT, Aborted.
0xb7fe1424 in __kernel_vsyscall ()
(gdb) back
#0  0xb7fe1424 in __kernel_vsyscall ()
#1  0xb7cba571 in raise () from /lib/libc.so.6
#2  0xb7cbbd72 in abort () from /lib/libc.so.6
#3  0xb7cb35e8 in __assert_fail () from /lib/libc.so.6
#4  0xb7bd4496 in driNewRenderbuffer () from /usr/lib/xorg/modules/dri/savage_dri.so
#5  0xb7c22ca0 in ?? () from /usr/lib/xorg/modules/dri/savage_dri.so
#6  0xb7c22c30 in ?? () from /usr/lib/xorg/modules/dri/savage_dri.so
#7  0x00000045 in ?? ()
#8  0xb7c22e2d in __PRETTY_FUNCTION__.24844 () from /usr/lib/xorg/modules/dri/savage_dri.so
#9  0x53065b34 in ?? ()
#10 0x00000070 in ?? ()
#11 0xb3e82a53 in ?? ()
#12 0xb7c274d0 in ?? () from /usr/lib/xorg/modules/dri/savage_dri.so
#13 0x0805cc80 in ?? ()
#14 0x0805c9a0 in ?? ()
#15 0x08322b78 in ?? ()
#16 0xb7bd4ee6 in savageCreateBuffer () from /usr/lib/xorg/modules/dri/savage_dri.so
#17 0x00000003 in ?? ()
#18 0xb07dd000 in ?? ()
#19 0x00000004 in ?? ()
#20 0x00000000 in ?? ()
(gdb) quit