You will have to create .nfont files if you plan on using the GNUstep libart backend. To do this, 
make sure that the "gnustep-mknfonts" package is installed. Then create a new directory and cd into it. 
Then run:
    mknfonts /usr/local/lib/X11/fonts/{Type1,TTF}/* /usr/local/lib/X11/fonts/{mscorefonts,freefont}/*

This will create a bunch of .nfont directories. Move them to /usr/local/GNUstep/System/Library/Fonts.
