Comment 12 for bug 798049

Hmm, it’s still not possible for me to install nvidia-current on x86_64 but configure it to not be used, because although x86_64-linux-gnu_GL.conf can be overridden by the mesa version, there is no mesa version of i386-linux-gnu_GL.conf, and nvidia’s i386-linux-gnu_GL.conf includes the 64-bit libraries too.

BTW, it seems unfriendly for the postinst to delete all non-multiarch gl_conf alternatives including those belonging to other packages. It should only delete the ones belonging to itself.