%rake erd Loading application environment... Loading code in search of Active Record models... Generating Entity-Relationship Diagram for 5 models... rake aborted! Saving diagram failed! Verify that Graphviz is installed and in your path, or use filetype=dot. /Library/Ruby/Gems/2.0.0/gems/rails-erd-1.1.0/lib/rails_erd/diagram/graphviz.rb:198:in `rescue in block in <class:Graphviz>' /Library/Ruby/G