built?

# File railties/lib/rails/gem_dependency.rb, line 130
    def built?
      return false unless frozen?

      if vendor_gem?
        specification.extensions.each do |ext|
          makefile = File.join(unpacked_gem_directory, File.dirname(ext), 'Makefile')
          return false unless File.exists?(makefile)
        end
      end

      true
    end