Why is bundler insisting on an exact gem version number when the gemspec states an open constraint?
问题 I'm contributing to the Ruby gem koudoku and trying to get Travis CI to work. The gem was set up with Travis a few days ago but all builds are failing with this error message (example): Bundler could not find compatible versions for gem "rack": In Gemfile: rspec-rails (~> 2.14.0) ruby depends on actionpack (>= 3.0) ruby depends on rack (~> 1.2.1) ruby capybara (>= 0) ruby depends on rack (1.0.0) The offending lines in the gemspec are: s.add_development_dependency "rspec-rails", "~> 2.14.0" s