This library is archived and will not be maintained. The recommended maintained alternative is FriendsOfBehat/SymfonyExtension.
There is also a fork at https://github.com/PHPExpertsInc/SymfonyExtension/ which added support for PHP 8.x and Symfony <= 7. It claims to be entirely backwards compatible with this library (meaning it shares the same architectural flaws that originally prompted the new extension). It is not officially recommended by the Behat maintainers, but it may be useful as a temporary migration path for existing projects.