/home/m/.rvm/rubies/ruby-2.2.0/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require': cannot load such file -- opengl (LoadError)
    from /home/m/.rvm/rubies/ruby-2.2.0/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /home/m/workspace/git/graphics/graphics/main/main.rb:1:in `<main>'