Catch exception for jobs storage directory

        self.shells = dict()

        #: jobs manager (different from MainLoop.jobs_manager)

        try:

            self.jobs_manager = JobsManager(logger, NodeJobsManagerInterface(self),

                                           JobsStore(self.main.config.jobs_store_path))

        except EnvironmentError as e:

            logger.critical('Cannot access jobs directory: %s', e.strerror)

            self.main.stop()

            raise

        #: loaded plugins

        self.plugins = {}  # plugin name -> plugin object