Your requirements could not be resolved to an installable set of packages. Problem 1 - maglnet/composer-require-checker 4.11.0 requires nikic/php-parser ^4.19.1 -> satisfiable by nikic/php-parser[v4.19.1]. - maglnet/composer-require-checker[4.9.0, ..., 4.10.0] require nikic/php-parser ^4.18.0 -> satisfiable by nikic/php-parser[v4.18.0, v4.19.0, v4.19.1]. - maglnet/composer-require-checker[4.7.0, ..., 4.8.0] require nikic/php-parser ^4.17.1 -> satisfiable by nikic/php-parser[v4.17.1, v4.18.0, v4.19.0, v4.19.1]. - maglnet/composer-require-checker 4.6.0 requires nikic/php-parser ^4.15.2 -> satisfiable by nikic/php-parser[v4.15.2, ..., v4.19.1]. - You can only install one version of a package, so only one of these can be installed: nikic/php-parser[v4.10.0, ..., v4.19.1, v5.0.0, v5.0.1, v5.0.2]. - infection/infection[0.28.0, ..., 0.28.1] require nikic/php-parser ^5.0 -> satisfiable by nikic/php-parser[v5.0.0, v5.0.1, v5.0.2]. - Root composer.json requires infection/infection ^0.28.0 -> satisfiable by infection/infection[0.28.0, 0.28.1]. - Root composer.json requires maglnet/composer-require-checker ^4.6.0 -> satisfiable by maglnet/composer-require-checker[4.6.0, ..., 4.11.0].