magallanes/tests/Resources/custom-task-not-instantiable.yml

magephp:
    environments:
        production:
            user: app
            host_path: /var/www/myapp
            hosts:
                - webserver
            pre-deploy:
            on-deploy:
                - custom-not-instantiable
            post-deploy:
    custom_tasks:
        - Mage\Tests\Task\Custom\NotInstantiableTask