Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpstan/phpstan ^2.0 -> satisfiable by phpstan/phpstan[2.0.x-dev]. - phpstan/phpstan 2.0.x-dev requires php ^7.4|^8.0 -> your php version (7.2.34) does not satisfy that requirement. Problem 2 - Root composer.json requires phpstan/phpstan-deprecation-rules ^2.0 -> satisfiable by phpstan/phpstan-deprecation-rules[2.0.x-dev]. - phpstan/phpstan-deprecation-rules 2.0.x-dev requires php ^7.4 || ^8.0 -> your php version (7.2.34) does not satisfy that requirement.