Your requirements could not be resolved to an installable set of packages. Problem 1 - sebastian/diff[4.0.0, ..., 4.0.1] require php ^7.3 -> your php version (8.2.16) does not satisfy that requirement. - Root composer.json requires phpunit/phpunit ~11.1.0 -> satisfiable by phpunit/phpunit[11.1.0]. - vimeo/psalm 5.9.0 requires sebastian/diff ^4.0 || ^5.0 -> satisfiable by sebastian/diff[4.0.0, ..., 4.0.6, 5.0.0, ..., 5.1.1]. - You can only install one version of a package, so only one of these can be installed: sebastian/diff[1.1.0, ..., 1.4.3, 2.0.1, 3.0.0, ..., 3.0.6, 4.0.0, ..., 4.0.6, 5.0.0, ..., 5.1.1, 6.0.0, 6.0.1]. - phpunit/phpunit 11.1.0 requires sebastian/diff ^6.0 -> satisfiable by sebastian/diff[6.0.0, 6.0.1]. - Root composer.json requires vimeo/psalm ~5.9.0 -> satisfiable by vimeo/psalm[5.9.0].