Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit ^12.0.0 -> satisfiable by phpunit/phpunit[12.0.0, 12.0.1, 12.0.2]. - phpunit/phpunit[12.0.0, ..., 12.0.2] require php >=8.3 -> your php version (8.2.99; overridden via config.platform, actual: 8.2.27) 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.