pytorch Default process group is not initialized

报错：Default process group is not initialized

报错代码，yolov5训练时不报错， 参数配置错了，

    with torch_distributed_zero_first(rank):
        dataset = LoadImagesAndLabels(path, imgsz, batch_size, augment=augment,  # augment images
                                      hyp=hyp,  # augmentation hyperparameters
                                      rect=rect,  # rectangular training
                                      cache_images=cache, single_cls=opt.single_cls, stride=int(stride), pad=pad, image_weights=image_weights, prefix=prefix,data_type=data_type)


@contextmanager
def torch_distributed_zero_first(local_rank: int):
    """
    Decorator to make all processes in distributed training wait for each local_master to do something.
    """
    if local_rank not in [-1, 0]:
        torch.distributed.barrier()
    yield
    if local_rank == 0: