Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit ^11.3.1 -> satisfiable by phpunit/phpunit[11.3.1]. - phpunit/phpunit 11.3.1 requires php >=8.2 -> your php version (8.0.99; overridden via config.platform, actual: 8.3.9) 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.