Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires infection/infection 0.27.11 -> satisfiable by infection/infection[0.27.11]. - infection/infection 0.27.11 requires nikic/php-parser ^4.15.1 -> satisfiable by nikic/php-parser[v4.15.1, ..., v4.19.4]. - You can only install one version of a package, so only one of these can be installed: nikic/php-parser[v4.13.0, ..., v4.19.4, v5.0.0, ..., v5.3.1]. - phpunit/php-code-coverage 11.0.7 requires nikic/php-parser ^5.3.1 -> satisfiable by nikic/php-parser[v5.3.1]. - phpunit/phpunit 11.4.2 requires phpunit/php-code-coverage ^11.0.7 -> satisfiable by phpunit/php-code-coverage[11.0.7]. - Root composer.json requires phpunit/phpunit ^11.4.2 -> satisfiable by phpunit/phpunit[11.4.2]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.