Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit ^11.2.7 -> satisfiable by phpunit/phpunit[11.2.7, 11.2.x-dev, 11.3.x-dev]. - phpunit/phpunit[11.2.7, ..., 11.3.x-dev] require php >=8.2 -> your php version (8.0.30) does not satisfy that requirement. Problem 2 - Root composer.json requires yoast/phpunit-polyfills ^2.0 -> satisfiable by yoast/phpunit-polyfills[2.0.0, 2.0.1, 2.x-dev]. - yoast/phpunit-polyfills[2.0.0, ..., 2.x-dev] require phpunit/phpunit ^5.7.21 || ^6.0 || ^7.0 || ^8.0 || ^9.0 || ^10.0 -> found phpunit/phpunit[5.7.21, ..., 5.7.27, 6.0.0, ..., 6.5.14, 7.0.0, ..., 7.5.20, 8.0.0, ..., 8.5.x-dev, 9.0.0, ..., 9.6.x-dev, 10.0.0, ..., 10.5.x-dev] but it conflicts with your root composer.json require (^11.2.7).