yolov5训练时，出现这种错误是什么意思呀？

Transferred 342/349 items from yolov5s.pt
Traceback (most recent call last):
  File "D:/yolov5-6.1/train.py", line 643, in <module>
    main(opt)
  File "D:/yolov5-6.1/train.py", line 539, in main
    train(opt.hyp, opt, device, callbacks)
  File "D:/yolov5-6.1/train.py", line 143, in train
    imgsz = check_img_size(opt.imgsz, gs, floor=gs * 2)  # verify imgsz is gs-multiple
AttributeError: 'Namespace' object has no attribute 'imgsz'

argparse模块里面的imgsz参数你没加上吗，原本应该有默认值的才对，你可以输出一下opt.imgsz看下图片大小对不对