Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit ~10.2.0 -> satisfiable by phpunit/phpunit[10.2.0, 10.2.1, 10.2.2, 10.2.3]. - phpunit/phpunit[10.2.0, ..., 10.2.3] require php >=8.1 -> your php version (8.0.29) does not satisfy that requirement. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.