Your lock file does not contain a compatible set of packages. Please run composer update. Problem 1 - phpunit/php-file-iterator is locked to version 4.1.0 and an update of this package was not requested. - You can only install one version of a package, so only one of these can be installed: phpunit/php-file-iterator[3.0.6, 4.1.0]. - phpunit/php-file-iterator is locked to version 3.0.6 and an update of this package was not requested.