Tip for 'libGL error: unable to find driver: atiogl_a_dri.so'

[William Knight <william dot knight at gmail dot com>]

I wanted to let others know of my solution for getting 3D acceleration
working for my Radeon 9250. I had to do a number of different things
to get it to work, but the final thing that really stumped me occured
because I had installed, at various times, both the ATI proprietary
drivers and the Debian ATI Linux drivers. The proprietary driver never
worked because it always failed trying to rebuild the kernel. So I
followed the instructions from Flavio at
http://xoomer.virgilio.it/flavio.stanchina/debian/fglrx-installer.html

and reached a point where no errors were reported in my
/var/log/Xorg.0.log file, but fglrxinfo still reported that the mesa
drivers were being used:

=================
$LIBGL_DEBUG=verbose fglrxinfo
libGL: XF86DRIGetClientDriverName: 8.19.10 atiogl_a (screen 0)
libGL: OpenDriver: trying
/usr/local/hw/ati//usr/X11R6/lib/modules/dri//atiogl_a_dri.so
libGL error: dlopen
/usr/local/hw/ati//usr/X11R6/lib/modules/dri//atiogl_a_dri.so failed
(/usr/local/hw/ati//usr/X11R6/lib/modules/dri//atiogl_a_dri.so: cannot
open shared object file: No such file or directory)
libGL error: unable to find driver: atiogl_a_dri.so
libGL: XF86DRIGetClientDriverName: 8.19.10 atiogl_a (screen 0)
libGL: OpenDriver: trying
/usr/local/hw/ati//usr/X11R6/lib/modules/dri//atiogl_a_dri.so
libGL error: dlopen
/usr/local/hw/ati//usr/X11R6/lib/modules/dri//atiogl_a_dri.so failed
(/usr/local/hw/ati//usr/X11R6/lib/modules/dri//atiogl_a_dri.so: cannot
open shared object file: No such file or directory)
libGL error: unable to find driver: atiogl_a_dri.so
display: :0.0  screen: 0
OpenGL vendor string: Mesa project: www.mesa3d.org
OpenGL renderer string: Mesa GLX Indirect
OpenGL version string: 1.2 (1.5 Mesa 6.2.1)
===================================

In my case, the error above occurs because libGL is trying to load the
driver from the strange path that got defined when I ran the ATI
installer. For a while, I couldn't figure out how this was being
specified, but for some reason I thought to do a grep on the /etc dir
for that path and found that the ATI installer had inserted some code
in /etc/profile that modified the LD_LIBRARY_PATH variable! Once I
removed that section from the file, my problem was solved!