Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires symplify/easy-coding-standard dev-main -> satisfiable by symplify/easy-coding-standard[dev-main]. - symplify/easy-coding-standard dev-main requires symplify/coding-standard ^12.0 -> satisfiable by symplify/coding-standard[12.0.0] from composer repo (https://repo.packagist.org) but symplify/coding-standard is the root package and cannot be modified. See https://getcomposer.org/dep-on-root for details and assistance.