seek help! TypeError: expected str, bytes or os.PathLike object, not NoneType

[DENESTY]

No description provided.

[DENESTY]

How to solve this
Traceback (most recent call last):
File "train_ssd.py", line 236, in
target_transform=target_transform, is_test=True)
File "/home/z/MobileNetV3-SSD-master/vision/datasets/voc_dataset.py", line 17, in init
self.root = pathlib.Path(root)
File "/usr/lib/python3.6/pathlib.py", line 1001, in new
self = cls._from_parts(args, init=False)
File "/usr/lib/python3.6/pathlib.py", line 656, in _from_parts
drv, root, parts = self._parse_args(args)
File "/usr/lib/python3.6/pathlib.py", line 640, in _parse_args
a = os.fspath(a)
TypeError: expected str, bytes or os.PathLike object, not NoneType

[jideee]

Hello bro！ Have you solved the problem？ I meet this same question in SSD.