docs: def fault_barrier(fn):
      """Method decorator to catch and log errors, then send fail message."""
      @functools.wraps(fn)
      def process(self, tup):
          try:
              return fn(self, tup)
          except Exception as e:
              if isinstance(e, KeyboardInterrupt):
                  return
              print(str(e), file=sys.stderr)
              self.fail(tup)
      return process