Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpstan/phpstan ^1.10.46, it is satisfiable by phpstan/phpstan[1.10.46, ..., 1.12.x-dev] from composer repo (https://repo.packagist.org) but phpstan/phpstan[2.0.x-dev] from path repo (../../..) has higher repository priority. The packages from the higher priority repository do not match your constraint and are therefore not installable. That repository is canonical so the lower priority repo's packages are not installable. See https://getcomposer.org/repoprio for details and assistance. Problem 2 - phpstan/extension-installer 1.4.x-dev requires phpstan/phpstan ^1.12.0 || ^2.0 -> found phpstan/phpstan[2.0.x-dev] but it conflicts with your root composer.json require (^1.10.46). - phpstan/extension-installer[1.3.1, ..., 1.4.2] require phpstan/phpstan ^1.9.0 -> satisfiable by phpstan/phpstan[1.9.0, ..., 1.12.x-dev] from composer repo (https://repo.packagist.org) but phpstan/phpstan[2.0.x-dev] from path repo (../../..) has higher repository priority. The packages from the higher priority repository do not match your constraint and are therefore not installable. That repository is canonical so the lower priority repo's packages are not installable. See https://getcomposer.org/repoprio for details and assistance. - phpstan/extension-installer 1.4.3 requires phpstan/phpstan ^1.9.0 || ^2.0 -> found phpstan/phpstan[2.0.x-dev] but it conflicts with your root composer.json require (^1.10.46). - Root composer.json requires phpstan/extension-installer ^1.3.1 -> satisfiable by phpstan/extension-installer[1.3.1, ..., 1.4.x-dev].