Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires maglnet/composer-require-checker ^4.7 -> satisfiable by maglnet/composer-require-checker[4.7.0, ..., 4.16.x-dev]. - Root composer.json requires roave/infection-static-analysis-plugin ^1.34 -> satisfiable by roave/infection-static-analysis-plugin[1.34.0, ..., 1.37.x-dev]. - infection/infection 0.29.10 requires nikic/php-parser ^5.3 -> satisfiable by nikic/php-parser[v5.3.0, v5.3.1, v5.4.0]. - maglnet/composer-require-checker[4.9.0, ..., 4.10.x-dev] require nikic/php-parser ^4.18.0 -> satisfiable by nikic/php-parser[v4.18.0, ..., 4.x-dev]. - maglnet/composer-require-checker[4.11.0, ..., 4.12.x-dev] require nikic/php-parser ^4.19.1 -> satisfiable by nikic/php-parser[v4.19.1, ..., 4.x-dev]. - maglnet/composer-require-checker[4.13.0, ..., 4.16.x-dev] require nikic/php-parser ^4.19.4 -> satisfiable by nikic/php-parser[v4.19.4, 4.x-dev]. - maglnet/composer-require-checker[4.7.0, ..., 4.8.x-dev] require nikic/php-parser ^4.17.1 -> satisfiable by nikic/php-parser[v4.17.1, ..., 4.x-dev]. - roave/infection-static-analysis-plugin[1.34.0, ..., 1.35.x-dev] require vimeo/psalm ^4.30.0 || ^5.15 -> found vimeo/psalm[4.30.0, 4.x-dev, 5.15.0, ..., 5.x-dev] but it conflicts with your root composer.json require (^6.0). - roave/infection-static-analysis-plugin[1.36.0, ..., 1.37.x-dev] require infection/infection 0.29.10 -> satisfiable by infection/infection[0.29.10]. - You can only install one version of a package, so only one of these can be installed: nikic/php-parser[v4.10.0, ..., 4.x-dev, v5.0.0alpha1, v5.0.0alpha2, v5.0.0alpha3, v5.4.0].