The gnuradius ebuild, version 1.3, contains a small typo in line 44: myconf="$myconf --with-client --with-server-guile" Instead of using --with-client, it should use --enable-client. Additionally, I'd like to suggest creating a local use flag "client", that would make it possible to install gnuradius with client support without having to install guile.
fixed in -r1 now --enable-client is forced no matter what USE you have. I choose this solution because it is hard for me to imagine that someone will want only client or server part of the gnuradius (the difference in disk space is insignifiant).