Ruby upstream have now officially deprecated the Ruby 1.8 branch, there will be no more updates. This means it is time for us to update packages that have exclusively been built on Ruby 1.8 to use Ruby 1.9. This could be as easy as defining USE_RUBY="ruby19" instead of ruby18, but might require more work or patches for (mostly older) packages with 1.9 compatibility issues. Feel free to ask in #gentoo-ruby if you have any questions. This page says: 1.9.3 is support for Ubuntu 13.04 "Ice for Ruby" http://www.zeroc.com/platforms_3_5_1.html
dev-lang/ruby:1.8 will be masked within a week. Since ruby support looks optional for you package please either fix the bindings or remove the ruby support before that time.
+ 26 Nov 2013; Sergey Popov <pinkbyte@gentoo.org> Ice-3.5.1.ebuild: + Use Ruby 1.9 for bindings as suggested by upstream, bug #490172 Tested, works fine.