Your requirements could not be resolved to an installable set of packages. Problem 1 - phpunit/phpunit[11.4.2, ..., 11.5.x-dev] require php >=8.2 -> your php version (8.1.30) does not satisfy that requirement. - Root composer.json requires phpunit/phpunit ^11.4.2 -> satisfiable by phpunit/phpunit[11.4.2, 11.4.x-dev, 11.5.x-dev]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.