RubyPython version 0.3 and higher are different than RubyPython through version 0.2.x. If you're upgrading from such an earlier version, make sure you read the documents for instructions on how your code needs to change to work with modern RubyPython. For more information on RubyPython, see: http://rubypython.rubyforge.org/ If you find a bug, or have any suggestions, please feel free to enter them on the tracker: https://bitbucket.org/raineszm/rubypython/issues?status=new&status=open If you would like to help develop RubyPython, please check out the source on Bitbucket: https://bitbucket.org/raineszm/rubypython/