Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpspec/prophecy-phpunit ^2.0 -> satisfiable by phpspec/prophecy-phpunit[v2.0.0, ..., v2.2.0]. - phpspec/prophecy[v1.18.0, ..., v1.19.0] require php ^7.2 || 8.0.* || 8.1.* || 8.2.* || 8.3.* -> your php version (8.4.0-dev) does not satisfy that requirement. - phpspec/prophecy-phpunit v2.0.0 requires php ^7.3 -> your php version (8.4.0-dev) does not satisfy that requirement. - phpspec/prophecy-phpunit[v2.0.1, ..., v2.0.2] require phpunit/phpunit ^9.1 -> found phpunit/phpunit[9.1.0, ..., 9.6.21] but it conflicts with your root composer.json require (^11.0|^10.0). - phpspec/prophecy-phpunit[v2.1.0, ..., v2.2.0] require phpspec/prophecy ^1.18 -> satisfiable by phpspec/prophecy[v1.18.0, v1.19.0].