* Build libSM with the system libuuid on Darwin (in such a way that we
don't get a rebuild on all other platforms).
svn path=/nixpkgs/trunk/; revision=17606
requires $out/share/X11/xkb/compiled to be writable, so symlink it
to /var/tmp. Using --with-xkb-output doesn't work in a chroot build
because `make install' tries to write a README.compiled file to
/var/tmp, which doesn't exist in the chroot.
svn path=/nixpkgs/trunk/; revision=17000
