1.6 release introduced breaking change. Installation on eZ 5 sites breaks with this error:
PHP Fatal error: Uncaught Symfony\Component\Debug\Exception\UndefinedMethodException: Attempted to call an undefined method named "arrayPrototype" of class "Symfony\Component\Config\Definition\Builder\ArrayNodeDefinition".
1.6
release introduced breaking change. Installation on eZ 5 sites breaks with this error: