public function main() {
		if (!class_exists('Robo\Runner')) {
			$this->err('<error>Unable to load Robo\Runner.</error>');
			$this->err('');
			$this->err('Make sure you have installed robo as a dependency,');
			$this->err('and that Robo\Runner is registered in your autoloader.');
			$this->err('');
			$this->err('If you are using composer run');
			$this->err('');
			$this->err('<info>$ php composer.phar require codegyre/robo</info>');
			$this->err('');
			return 1;
		}

		array_shift($_SERVER['argv']);

		$runner = new Runner();
		$runner->file = $this->params['config'];
		$runner->execute();
	}