vendor/rails/railties/lib/ruby_version_check.rb

   1 min_release  = "1.8.2 (2004-12-25)"
   2 ruby_release = "#{RUBY_VERSION} (#{RUBY_RELEASE_DATE})"
   3 if ruby_release =~ /1\.8\.3/
   4   abort <<-end_message
   5
   6     Rails does not work with Ruby version 1.8.3.
   7     Please upgrade to version 1.8.4 or downgrade to 1.8.2.
   8
   9   end_message
  10 elsif ruby_release < min_release
  11   abort <<-end_message
  12
  13     Rails requires Ruby version #{min_release} or later.
  14     You're running #{ruby_release}; please upgrade to continue.
  15
  16   end_message
  17 end