when you run rake, it fails.
EXAMPLE:
$ rake
rake aborted!
Don't know how to build task 'default'
/Users/joenorton/.rvm/gems/ruby-2.1.2-mri/bin/ruby_executable_hooks:15:in eval' /Users/joenorton/.rvm/gems/ruby-2.1.2-mri/bin/ruby_executable_hooks:15:in

'
(See full trace by running task with --trace)