Debian packages Festival, so it seems there is a way to get a free-software version of it working, but Gentoo's ebuild unconditionally requires the non-free "free-noncomm" license for it (with no explanation of what components it's relevant for). There should be a USE flag to disable any non-free additions in Gentoo's festival.
The problem is in voice files. Not all of them are free. I'll see what I can do to separate them.
I wouldn't put a lot of effort into splitting up the package like this because I don't know of any other packages in Gentoo which split up upstream packages based on licenses.
(In reply to William Hubbs from comment #2) > I wouldn't put a lot of effort into splitting up the package like this > because I don't know of any other packages in Gentoo which split up > upstream packages based on licenses. The code itself is free (though some sublicenses). Some of voice files which we download separately are not. Debian splits them so this is not a huge problem. They are separate SRC_URI anyway. The problem why it takes so long is more trivial: lack of time, since these days I can spend only part of my weekends for Gentoo. Since August 2th I'll have a vacation for couple of weeks, so I should have time then.
Package(s) removed.