}
	nextfd++

	// Allocate another pipe for parent to child communication for
	// synchronizing writing of User ID/Group ID mappings.
	if sys.UidMappings != nil || sys.GidMappings != nil {
		if err := forkExecPipe(mapPipe[:]); err != nil {
			err1 = err.(Errno)
			return
		}
	}

	flags = sys.Cloneflags
	if sys.Cloneflags&CLONE_NEWUSER == 0 && sys.Unshareflags&CLONE_NEWUSER == 0 {
		flags |= CLONE_VFORK | CLONE_VM