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]. - phpunit/phpunit[12.0.0, ..., 12.0.1] require php >=8.3 -> your php version (8.2.27) does not satisfy that requirement. Problem 2 - Root composer.json requires phpspec/prophecy-phpunit ^2.1.0 -> satisfiable by phpspec/prophecy-phpunit[v2.1.0, v2.2.0, v2.3.0]. - phpspec/prophecy-phpunit v2.1.0 requires phpunit/phpunit ^9.1 || ^10.1 -> found phpunit/phpunit[9.1.0, ..., 9.6.22, 10.1.0, ..., 10.5.45] but it conflicts with your root composer.json require (^12.0.0). - phpspec/prophecy-phpunit[v2.2.0, ..., v2.3.0] require phpunit/phpunit ^9.1 || ^10.1 || ^11.0 -> found phpunit/phpunit[9.1.0, ..., 9.6.22, 10.1.0, ..., 10.5.45, 11.0.0, ..., 11.5.7] but it conflicts with your root composer.json require (^12.0.0). Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.