ruby Install ruby tests that can only be run after ruby is installed Use the sys-libs/readline library to provide the readline extension, used for instance by the irb tool. This flag is meaningful only if the libedit USE flag is disabled. If neither libedit nor readline USE flags are enabled, the readline extension will not be built (and irb will lose line editing functionality). Use the dev-libs/libyaml library to build the psych extension, available since Ruby 1.9.2_rc2, in alternative to the bundled syck-based parser. Install dev-ruby/rdoc after installing Ruby. Use dev-libs/jemalloc for memory allocation.