Snow Leo ships with ctags not suitable for Ruby development. Ie if you try to generate tags recursively, it will error out: $ ctags -R ctags: illegal option -- R usage: ctags [-BFadtuwvx] [-f tagsfile] file ... $ which ctags /usr/bin/ctags homebrew to the rescue: $ brew install ctags ==> Downloading http://downloads.sourceforge.net/ctags/ctags-5.8.tar.gz ###########################################