code: def fatal(self, msg, exc=None):
          
          if exc is not None:
              self.LOG.fatal("%s (%s)" % (msg, exc))
              if self.options.debug:
                  return # let the caller re-raise it
          else:
              self.LOG.fatal(msg)
          sys.exit(error.EX_SOFTWARE)
docs: Exit on a fatal error.