Your requirements could not be resolved to an installable set of packages. Problem 1 - phpunit/phpunit[9.6.0, ..., 9.6.11] require phpunit/php-code-coverage ^9.2.13 -> satisfiable by phpunit/php-code-coverage[9.2.13, ..., 9.2.x-dev] from composer repo (https://repo.packagist.org) but phpunit/php-code-coverage is the root package and cannot be modified. See https://getcomposer.org/dep-on-root for details and assistance. - phpunit/phpunit[9.6.12, ..., 9.6.19] require phpunit/php-code-coverage ^9.2.28 -> satisfiable by phpunit/php-code-coverage[9.2.28, ..., 9.2.x-dev] from composer repo (https://repo.packagist.org) but phpunit/php-code-coverage is the root package and cannot be modified. See https://getcomposer.org/dep-on-root for details and assistance. - phpunit/phpunit 9.6.20 requires phpunit/php-code-coverage ^9.2.31 -> satisfiable by phpunit/php-code-coverage[9.2.31, 9.2.x-dev] from composer repo (https://repo.packagist.org) but phpunit/php-code-coverage is the root package and cannot be modified. See https://getcomposer.org/dep-on-root for details and assistance. - Root composer.json requires phpunit/phpunit ^9.6 -> satisfiable by phpunit/phpunit[9.6.0, ..., 9.6.20].