testing.rb

require 'treetop'
#=> true

require 'polyglot'
#=> false

# I would expect polyglot to not have been required already

treetop_docs

In order to use Polyglot dynamic loading of .treetop or .tt files though, you need to require the Polyglot gem before you require the Treetop gem as Treetop will only create hooks into Polyglot for the treetop files if Polyglot is already loaded. So you need to use:

require 'polyglot'
require 'treetop'
in order to use Polyglot auto loading with Treetop in Ruby.