find pkgs -name "*.nix" -exec sed -r \ "s|https?://downloads.sourceforge.net/|mirror://sourceforge/|g" -i {} \;
This seems to have been confusing people, using both xlibs and xorg, etc. - Avoided renaming local (and different) xlibs binding in gcc*. - Fixed cases where both xorg and xlibs were used. Hopefully everything still works as before.