Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires symfony/var-dumper 6.3.8 as 6.1.3 -> satisfiable by symfony/var-dumper[v6.3.8]. - symfony/var-dumper v6.3.8 requires php >=8.1 -> your php version (8.0.30) does not satisfy that requirement. Problem 2 - symfony/var-dumper v6.3.8 requires php >=8.1 -> your php version (8.0.30) does not satisfy that requirement. - pestphp/pest-dev-tools[v1.0.0, ..., 1.x-dev] require symfony/var-dumper ^5.4.11 || ^6.1.3 -> satisfiable by symfony/var-dumper[6.1.3 (alias of v6.3.8), v6.3.8]. - symfony/var-dumper 6.1.3 is an alias of symfony/var-dumper v6.3.8 and thus requires it to be installed too. - Root composer.json requires pestphp/pest-dev-tools ^1.0.0 -> satisfiable by pestphp/pest-dev-tools[v1.0.0, 1.x-dev].