I'm running Snow Leopard, and installed a custom built Ruby according to the guide here: http://hivelogic.com/articles/compiling-ruby-rubygems-and-rails-on-snow-leopard . My ruby binary lives in usr/local/bin/ruby and my gems are installed in /usr/local/bin/gem . My gem env looks like so: RUBY VERSION: 1.8.7 (2008-08-11 patchlevel 72) [universal-darwin10.0] - INSTALLATION DIRECTORY: /Library/Ruby/Gems/1.8 - RUBY EXECUTABLE: /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby - EXECUTABLE DIRECTORY: /usr/bin I think I may have borked the install since all actions taked on gems give the error: ERROR: While executing gem ... (Errno::EEXIST) File exists - /usr/local/bin/ruby How do you edit the environment variables for the gem environment? And for those of you on OS X and using ruby AND gems, what did you use to get yourself up and running? I'm thinking of just nuking everything and starting anew.