I have an issue when trying to set up rvm, where gems weren't installing due to them being dependent on json_pure. I tried to install json_pure, but rubygems itself seems to depend on json_pure. I have tried removing all versions of json_pure, but rubygems still complains. $ sudo gem install json_pure /Library/Ruby/Site/1.8/rubygems.rb:777:in `report_activate_error': Could not find RubyGem json_pure (= 0) (Gem::LoadError) I have tried downloading the gem and installing it locally, but rubygems still complains about the dependency.