i don't understand this error can someone pleas help me ?
/var/lib/gems/1.9.1/gems/bowline-bundler-0.0.4/lib/bowline/bundler/dependency.rb:59:in class:Dependency': undefined methodversion_requirements' for class Bundler::Dependency' (NameError) from /var/lib/gems/1.9.1/gems/bowline-bundler-0.0.4/lib/bowline/bundler/dependency.rb:4:in' from /var/lib/gems/1.9.1/gems/bowline-bundler-0.0.4/lib/bowline/bundler/dependency.rb:1:in <top (required)>' from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:inrequire' from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in require' from /var/lib/gems/1.9.1/gems/bowline-bundler-0.0.4/lib/bowline/bundler.rb:18:in' from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in require' from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:inrequire' from /var/lib/gems/1.9.1/gems/bowline-bundler-0.0.4/bin/bowline-bundle:4:in <top (required)>' from /usr/local/bin/bowline-bundle:23:inload' from /usr/local/bin/bowline-bundle:23:in `'
i don't understand this error can someone pleas help me ?
/var/lib/gems/1.9.1/gems/bowline-bundler-0.0.4/lib/bowline/bundler/dependency.rb:59:in class:Dependency': undefined methodversion_requirements' for class Bundler::Dependency' (NameError) from /var/lib/gems/1.9.1/gems/bowline-bundler-0.0.4/lib/bowline/bundler/dependency.rb:4:in' from /var/lib/gems/1.9.1/gems/bowline-bundler-0.0.4/lib/bowline/bundler/dependency.rb:1:in <top (required)>' from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:inrequire' from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in require' from /var/lib/gems/1.9.1/gems/bowline-bundler-0.0.4/lib/bowline/bundler.rb:18:in' from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in require' from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:inrequire' from /var/lib/gems/1.9.1/gems/bowline-bundler-0.0.4/bin/bowline-bundle:4:in <top (required)>' from /usr/local/bin/bowline-bundle:23:inload' from /usr/local/bin/bowline-bundle:23:in `'