# File lib/pry/default_commands/gems.rb, line 19
        def process(gem)
          begin
            destination = File.writable?(Gem.dir) ? Gem.dir : Gem.user_dir
            installer = Gem::DependencyInstaller.new :install_dir => destination
            installer.install gem
          rescue Errno::EACCES
            raise CommandError, "Insufficient permissions to install `#{text.green gem}`."
          rescue Gem::GemNotFoundException
            raise CommandError, "Gem `#{text.green gem}` not found."
          else
            Gem.refresh
            output.puts "Gem `#{text.green gem}` installed."
          end
        end