For instance, using this Gemfile(5):
source "https://rubygems.org" ruby "1.9.3" gem "rack"
If you run bundle platform on Ruby 1.9.3, it will display the following output:
Your platform is: x86_64-linux Your app has gems that work on these platforms: * ruby Your Gemfile specifies a Ruby version requirement: * ruby 1.9.3 Your current platform satisfies the Ruby version requirement.
platform will list all the platforms in your Gemfile.lock as well as the ruby directive if applicable from your Gemfile(5). It will also let you know if the ruby directive requirement has been met. If ruby directive doesn't match the running Ruby VM, it will tell you what part does not.