# File lib/pry/rubygem.rb, line 19
      def spec(name)
        specs = if Gem::Specification.respond_to?(:each)
                  Gem::Specification.find_all_by_name(name)
                else
                  Gem.source_index.find_name(name)
                end

        first_spec = specs.sort_by{ |spec| Gem::Version.new(spec.version) }.last

        first_spec or raise CommandError, "Gem `#{name}` not found"
      end