Broken Ruby

brew cask output

[~]$ brew cask                                                                                                       *[master][2.0.0-p481]
Error: uninitialized constant Gem::UserInteraction
Please report this bug:
    https://github.com/Homebrew/homebrew/wiki/troubleshooting
/Library/Ruby/Site/1.8/rubygems/ext/builder.rb:12
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `require'
/Library/Ruby/Site/1.8/rubygems/ext.rb:13
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `require'
/Library/Ruby/Site/1.8/rubygems/specification.rb:1431:in `build_extensions'
/Library/Ruby/Site/1.8/rubygems/stub_specification.rb:60:in `build_extensions'
/Library/Ruby/Site/1.8/rubygems/basic_specification.rb:56:in `contains_requirable_file?'
/Library/Ruby/Site/1.8/rubygems/specification.rb:925:in `find_inactive_by_path'
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `find'
/Library/Ruby/Site/1.8/rubygems/specification.rb:924:in `each'
/Library/Ruby/Site/1.8/rubygems/specification.rb:924:in `find'
/Library/Ruby/Site/1.8/rubygems/specification.rb:924:in `find_inactive_by_path'
/Library/Ruby/Site/1.8/rubygems.rb:185:in `try_activate'
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:132:in `require'
/Library/Ruby/Site/1.8/rubygems/user_interaction.rb:8
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `require'
/Library/Ruby/Site/1.8/rubygems/config_file.rb:7
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `require'
/Library/Ruby/Site/1.8/rubygems/specification.rb:1430:in `build_extensions'
/Library/Ruby/Site/1.8/rubygems/stub_specification.rb:60:in `build_extensions'
/Library/Ruby/Site/1.8/rubygems/basic_specification.rb:56:in `contains_requirable_file?'
/Library/Ruby/Site/1.8/rubygems/specification.rb:925:in `find_inactive_by_path'
/Library/Ruby/Site/1.8/rubygems/specification.rb:1031:in `find'
/Library/Ruby/Site/1.8/rubygems/specification.rb:924:in `each'
/Library/Ruby/Site/1.8/rubygems/specification.rb:924:in `find'
/Library/Ruby/Site/1.8/rubygems/specification.rb:924:in `find_inactive_by_path'
/Library/Ruby/Site/1.8/rubygems.rb:185:in `try_activate'
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:132:in `require'
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/tmpdir.rb:14
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `require'
/usr/local/Cellar/brew-cask/0.35.0/rubylib/cask/container/unarbase.rb:1
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `require'
/usr/local/Cellar/brew-cask/0.35.0/rubylib/cask/container.rb:4
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `require'
/usr/local/Cellar/brew-cask/0.35.0/rubylib/cask.rb:18
/usr/local/bin/brew-cask.rb:4:in `require'
/usr/local/bin/brew-cask.rb:4
/usr/local/Library/brew.rb:64:in `require'
/usr/local/Library/brew.rb:64:in `require?'
/usr/local/Library/brew.rb:111