Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit ^11.1.2 -> satisfiable by phpunit/phpunit[11.1.2]. - vimeo/psalm 5.23.1 requires nikic/php-parser ^4.16 -> satisfiable by nikic/php-parser[v4.16.0, ..., v4.19.1]. - You can only install one version of a package, so only one of these can be installed: nikic/php-parser[v4.16.0, ..., v4.19.1, v5.0.0, v5.0.1, v5.0.2]. - phpunit/php-code-coverage[11.0.0, ..., 11.0.3] require nikic/php-parser ^5.0 -> satisfiable by nikic/php-parser[v5.0.0, v5.0.1, v5.0.2]. - vimeo/psalm 5.23.1 conflicts with nikic/php-parser v4.17.0. - phpunit/phpunit 11.1.2 requires phpunit/php-code-coverage ^11.0 -> satisfiable by phpunit/php-code-coverage[11.0.0, 11.0.1, 11.0.2, 11.0.3]. - Root composer.json requires vimeo/psalm ^5.23.1 -> satisfiable by vimeo/psalm[5.23.1].