Comment 3 for bug 1060492

This is all I get when I try to get a full backtrace.

sudo gdb /usr/bin/Xorg /etc/X11/core

GNU gdb (GDB) 7.5-ubuntu
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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 "i686-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/bin/Xorg...Reading symbols from /usr/lib/debug/usr/bin/Xorg...done.
done.

warning: exec file is newer than core file.
[New LWP 1199]

warning: Can't read pathname for load map: Input/output error.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
Core was generated by `/usr/bin/X :0 -core -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitc'.
Program terminated with signal 6, Aborted.
#0 0xb7584424 in __kernel_vsyscall ()
(gdb) backtrace full
#0 0xb7584424 in __kernel_vsyscall ()
No symbol table info available.
#1 0xb721c1cf in raise () from /lib/i386-linux-gnu/libc.so.6
No symbol table info available.
#2 0xb721f815 in abort () from /lib/i386-linux-gnu/libc.so.6
No symbol table info available.
#3 0xb7755159 in OsReleaseSIGIO () at ../../os/utils.c:1229
No locals.
#4 0xb77c6000 in ?? ()
No symbol table info available.
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb)