If you want to use this package as your default system ruby, as root
create symbolic links like so (overwriting any previous default):
 ln -sf ${PREFIX}/bin/ruby23 ${PREFIX}/bin/ruby
 ln -sf ${PREFIX}/bin/erb23 ${PREFIX}/bin/erb
 ln -sf ${PREFIX}/bin/irb23 ${PREFIX}/bin/irb
 ln -sf ${PREFIX}/bin/rdoc23 ${PREFIX}/bin/rdoc
 ln -sf ${PREFIX}/bin/ri23 ${PREFIX}/bin/ri
 ln -sf ${PREFIX}/bin/rake23 ${PREFIX}/bin/rake
 ln -sf ${PREFIX}/bin/gem23 ${PREFIX}/bin/gem
