Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit ~11.0.0 -> satisfiable by phpunit/phpunit[11.0.0, 11.0.1]. - You can only install one version of a package, so only one of these can be installed: nikic/php-parser[v4.0.0, ..., v4.18.0, v5.0.0]. - phpunit/php-code-coverage 11.0.0 requires nikic/php-parser ^5.0 -> satisfiable by nikic/php-parser[v5.0.0]. - vimeo/psalm 5.9.0 requires nikic/php-parser ^4.14 -> satisfiable by nikic/php-parser[v4.14.0, ..., v4.18.0]. - phpunit/phpunit[11.0.0, ..., 11.0.1] require phpunit/php-code-coverage ^11.0 -> satisfiable by phpunit/php-code-coverage[11.0.0]. - Root composer.json requires vimeo/psalm ~5.9.0 -> satisfiable by vimeo/psalm[5.9.0].