mkvtoolnix 7.5.0 compiles and runs fine with ruby 2.2 installed. Currently, only 2.0 and 2.1 are supported in the ebuild file. Reproducible: Always Steps to Reproduce: 1. run "emerge mkvtoolnix" with only ruby 2.2 installed Actual Results: Ruby 2.1 is pulled in for installation Expected Results: mkvtoolnix installs with rake for/from ruby 2.2 Fixing should be as easy as adding "ruby22" to variable RUBY_IMPLS inside the ebuild. The same applies for 7.4.0. I haven't tested it with older versions.
Fixed in 7.5.0.