MRuby::GemBox.new do |conf| conf.gem :core => "mruby-sprintf" conf.gem :core => "mruby-print" Dir.glob("#{root}/mrbgems/mruby-*/mrbgem.rake") do |x| g = File.basename File.dirname x conf.gem :core => g unless g =~ /^mruby-(print|sprintf|bin-debugger|test)$/ end end