Fix Rubygems error: undefined method `source_index' for Gem:Module
You are probably using Ruby 1.8.7 with a too recent versions of Rubygems.
Downgrade your Rubygems to the latest version that works with 1.8.7.
You are probably using Ruby 1.8.7 with a too recent versions of Rubygems.
Downgrade your Rubygems to the latest version that works with 1.8.7.