Your requirements could not be resolved to an installable set of packages. Problem 1 - phpspec/prophecy[dev-master, v1.16.0, ..., v1.17.0] require php ^7.2 || 8.0.* || 8.1.* || 8.2.* -> your php version (8.3.0-dev) does not satisfy that requirement. - phpspec/prophecy 1.11.1 requires php ^7.2 -> your php version (8.3.0-dev) does not satisfy that requirement. - phpspec/prophecy[1.12.0, ..., 1.13.0] require php ^7.2 || ~8.0, <8.1 -> your php version (8.3.0-dev) does not satisfy that requirement. - phpspec/prophecy[1.14.0, ..., v1.15.0] require php ^7.2 || ~8.0, <8.2 -> your php version (8.3.0-dev) does not satisfy that requirement. - phpunit/phpunit 9.3.0 requires phpspec/prophecy ^1.11.1 -> satisfiable by phpspec/prophecy[1.11.1, ..., 1.x-dev (alias of dev-master)]. - phpspec/prophecy 1.x-dev is an alias of phpspec/prophecy dev-master and thus requires it to be installed too. - Root composer.json requires phpunit/phpunit 9.3.0 -> satisfiable by phpunit/phpunit[9.3.0].