C:\tmp>composer require "twig/twig:~1.0" You are running composer with xdebug enabled. This has a major impact on runtime performance. See https://getcomposer.or g/xdebug ./composer.json has been created Loading composer repositories with package information Updating dependencies (including require-dev) - Installing twig/twig (v1.24.0) Loading from cache Writing lock file Generating autoload files