code: func WithClearedCloExec(lfd int, f func() error) error {
  	err := sys.CloseOnExec(lfd, false)
  	if err != nil {
  		return err
  	}
  	defer sys.CloseOnExec(lfd, true)
  
  	return f()
  }
docs: // WithClearedCloExec executes a given function in between setting and unsetting the close-on-exit flag
  // on the given file descriptor