code: def enable_death_signal(_warn=True):
      
      if platform.system() != 'Linux':
          return
      try:
          import prctl    # pip install python-prctl
      except ImportError:
          if _warn:
              log_once('"import prctl" failed! Install python-prctl so that processes can be cleaned with guarantee.',
                       'warn')
          return
      else:
          assert hasattr(prctl, 'set_pdeathsig'), \
              "prctl.set_pdeathsig does not exist! Note that you need to install 'python-prctl' instead of 'prctl'."
          # is SIGHUP a good choice?
          prctl.set_pdeathsig(signal.SIGHUP)
docs: Set the "death signal" of the current process, so that
      the current process will be cleaned with guarantee
      in case the parent dies accidentally.