ruby 2.0.0p0 : DL is deprecated, please use Fiddle

The message you received it's common on  ruby 2.0.0p0 (2013-02-24) on top ofWindows

The message "DL is deprecated, please use Fiddle" is not an error; it's only a warninig

The source is the Deprecation notice for DL introduced some time ago in dl.rb ( seerevisions/37910 )

On Windows the lib/ruby/site_ruby/2.0.0/readline.rb still requiredl.rb so thewarning message come out when you require 'irb' ( because irb require 'readline' ) or anything else wants torequire 'readline'

You can open with your favorite editor the readline.rb and look up the code ( nearby line 4369)

   if RUBY_VERSION < '1.9.1'      require 'Win32API'    else      require 'dl'      class Win32API        DLL = {}

We can hope for an improvement in work out this deprecation in future release ofruby