Your lock file does not contain a compatible set of packages. Please run composer update. Problem 1 - phpstan/phpstan-deprecation-rules is locked to version dev-master and an update of this package was not requested. - phpstan/phpstan-deprecation-rules dev-master requires phpstan/phpstan ^1.0 -> could not be found in any version, there may be a typo in the package name. Problem 2 - phpstan/phpstan-nette is locked to version dev-master and an update of this package was not requested. - phpstan/phpstan-nette dev-master requires phpstan/phpstan ^1.0 -> could not be found in any version, there may be a typo in the package name. Problem 3 - phpstan/phpstan-php-parser is locked to version dev-master and an update of this package was not requested. - phpstan/phpstan-php-parser dev-master requires phpstan/phpstan ^1.0 -> could not be found in any version, there may be a typo in the package name. Problem 4 - phpstan/phpstan-phpunit is locked to version dev-master and an update of this package was not requested. - phpstan/phpstan-phpunit dev-master requires phpstan/phpstan ^1.0 -> could not be found in any version, there may be a typo in the package name. Problem 5 - phpstan/phpstan-strict-rules is locked to version dev-master and an update of this package was not requested. - phpstan/phpstan-strict-rules dev-master requires phpstan/phpstan ^1.0 -> could not be found in any version, there may be a typo in the package name. Problem 6 - phpstan/phpstan-deprecation-rules is locked to version 1.0.x-dev and an update of this package was not requested. - phpstan/phpstan-deprecation-rules dev-master requires phpstan/phpstan ^1.0 -> could not be found in any version, there may be a typo in the package name. - phpstan/phpstan-deprecation-rules 1.0.x-dev is an alias of phpstan/phpstan-deprecation-rules dev-master and thus requires it to be installed too. Potential causes: - A typo in the package name - The package is not available in a stable-enough version according to your minimum-stability setting see <https://getcomposer.org/doc/04-schema.md#minimum-stability> for more details. - It's a private package and you forgot to add a custom repository to find it Read <https://getcomposer.org/doc/articles/troubleshooting.md> for further common problems.