The ebuild unconditionally inherits ruby-ng, but also only supports ruby18. As such, the eclass kills any attempt to build, even with USE=-ruby, unless the now deprecated ruby18 is in RUBY_TARGETS. It looks like the ebuild shouldn’t inherit ruby-ng unless ruby is in USE. More invasively, given the deprecation of ruby18, should drop all ruby support until and unless a new version of epic5 supports a newer ruby release. With ruby elided, the ebuild for 1.1.2 works.
25 Mar 2014; Nathan Phillip Brink <binki@gentoo.org> epic5-1.1.2.ebuild: Fix ability to compile with USE=-ruby for bug #497080. Sorry for being so slow. Also, the issue was me misunderstanding ruby-ng.eclass, not ruby-ng.eclass, see bug #489608 for details. The solution turns out to be making the ruby-ng_pkg_setup() call conditional instead of implicitly unconditional. Thanks much for the report. Now to make epic5 work with ruby19 and/or version bump it…