Depends if you're using 32 bits programs (requiring a package of 32libs) or not.
For me it is (for you it might not be if you don't have that directory): paulo@AIVAS:~$ echo $LIBGL_DRIVERS_PATH /usr/lib/dri:/usr/lib32/dri
Depends if you're using 32 bits programs (requiring a package of 32libs) or
not.
For me it is (for you it might not be if you don't have that directory): dri:/usr/ lib32/dri
paulo@AIVAS:~$ echo $LIBGL_DRIVERS_PATH
/usr/lib/