AttributeError: 'Exp' object has no attribute 'perspective'

I used the latest code of 3.19 to train my data set on nano and found such an error. How can I solve this problem

(mypytorch) D:\ProgramData\YOLOX>python tools/train.py -f exps/example/yolox_voc/yolox_voc_nano.py -d 1 -b 16 --fp16 -o -c weights/yolox_nano.pth --cache
2022-03-18 23:52:55 | INFO | yolox.core.trainer:129 - args: Namespace(batch_size=16, cache=True, ckpt='weights/yolox_nano.pth', devices=1, dist_backend='nccl', dist_url=None, exp_file='exps/example/yolox_voc/yolox_voc_nano.py', experiment_name='yolox_voc_nano', fp16=True, logger='tensorboard', machine_rank=0, name=None, num_machines=1, occupy=True, opts=[], resume=False, start_epoch=None)
2022-03-18 23:52:55 | INFO | yolox.core.trainer:130 - exp value:
╒═══════════════════╤════════════════════════════╕
│ keys │ values │
╞═══════════════════╪════════════════════════════╡
│ seed │ None │
├───────────────────┼────────────────────────────┤
│ output_dir │ './YOLOX_outputs' │
├───────────────────┼────────────────────────────┤
│ print_interval │ 10 │
├───────────────────┼────────────────────────────┤
│ eval_interval │ 10 │
├───────────────────┼────────────────────────────┤
│ num_classes │ 1 │
├───────────────────┼────────────────────────────┤
│ depth │ 0.33 │
├───────────────────┼────────────────────────────┤
│ width │ 0.25 │
├───────────────────┼────────────────────────────┤
│ act │ 'silu' │
├───────────────────┼────────────────────────────┤
│ data_num_workers │ 4 │
├───────────────────┼────────────────────────────┤
│ input_size │ (416, 416) │
├───────────────────┼────────────────────────────┤
│ multiscale_range │ 5 │
├───────────────────┼────────────────────────────┤
│ data_dir │ None │
├───────────────────┼────────────────────────────┤
│ train_ann │ 'instances_train2017.json' │
├───────────────────┼────────────────────────────┤
│ val_ann │ 'instances_val2017.json' │
├───────────────────┼────────────────────────────┤
│ test_ann │ 'instances_test2017.json' │
├───────────────────┼────────────────────────────┤
│ mosaic_prob │ 0.5 │
├───────────────────┼────────────────────────────┤
│ mixup_prob │ 1.0 │
├───────────────────┼────────────────────────────┤
│ hsv_prob │ 1.0 │
├───────────────────┼────────────────────────────┤
│ flip_prob │ 0.5 │
├───────────────────┼────────────────────────────┤
│ degrees │ 10.0 │
├───────────────────┼────────────────────────────┤
│ translate │ 0.1 │
├───────────────────┼────────────────────────────┤
│ mosaic_scale │ (0.5, 1.5) │
├───────────────────┼────────────────────────────┤
│ enable_mixup │ False │
├───────────────────┼────────────────────────────┤
│ mixup_scale │ (0.5, 1.5) │
├───────────────────┼────────────────────────────┤
│ shear │ 2.0 │
├───────────────────┼────────────────────────────┤
│ warmup_epochs │ 1 │
├───────────────────┼────────────────────────────┤
│ max_epoch │ 300 │
├───────────────────┼────────────────────────────┤
│ warmup_lr │ 0 │
├───────────────────┼────────────────────────────┤
│ min_lr_ratio │ 0.05 │
├───────────────────┼────────────────────────────┤
│ basic_lr_per_img │ 0.00015625 │
├───────────────────┼────────────────────────────┤
│ scheduler │ 'yoloxwarmcos' │
├───────────────────┼────────────────────────────┤
│ no_aug_epochs │ 15 │
├───────────────────┼────────────────────────────┤
│ ema │ True │
├───────────────────┼────────────────────────────┤
│ weight_decay │ 0.0005 │
├───────────────────┼────────────────────────────┤
│ momentum │ 0.9 │
├───────────────────┼────────────────────────────┤
│ save_history_ckpt │ True │
├───────────────────┼────────────────────────────┤
│ exp_name │ 'yolox_voc_nano' │
├───────────────────┼────────────────────────────┤
│ test_size │ (416, 416) │
├───────────────────┼────────────────────────────┤
│ test_conf │ 0.01 │
├───────────────────┼────────────────────────────┤
│ nmsthre │ 0.65 │
├───────────────────┼────────────────────────────┤
│ random_size │ (10, 20) │
╘═══════════════════╧════════════════════════════╛
2022-03-18 23:52:55 | INFO | yolox.core.trainer:135 - Model Summary: Params: 0.90M, Gflops: 1.04
2022-03-18 23:52:55 | INFO | yolox.core.trainer:307 - loading checkpoint for fine tuning
2022-03-18 23:52:55 | WARNING | yolox.utils.checkpoint:24 - Shape of head.cls_preds.0.weight in checkpoint is torch.Size([80, 64, 1, 1]), while shape of head.cls_preds.0.weight in model is torch.Size([1, 64, 1, 1]).
2022-03-18 23:52:55 | WARNING | yolox.utils.checkpoint:24 - Shape of head.cls_preds.0.bias in checkpoint is torch.Size([80]), while shape of head.cls_preds.0.bias in model is torch.Size([1]).
2022-03-18 23:52:55 | WARNING | yolox.utils.checkpoint:24 - Shape of head.cls_preds.1.weight in checkpoint is torch.Size([80, 64, 1, 1]), while shape of head.cls_preds.1.weight in model is torch.Size([1, 64, 1, 1]).
2022-03-18 23:52:55 | WARNING | yolox.utils.checkpoint:24 - Shape of head.cls_preds.1.bias in checkpoint is torch.Size([80]), while shape of head.cls_preds.1.bias in model is torch.Size([1]).
2022-03-18 23:52:55 | WARNING | yolox.utils.checkpoint:24 - Shape of head.cls_preds.2.weight in checkpoint is torch.Size([80, 64, 1, 1]), while shape of head.cls_preds.2.weight in model is torch.Size([1, 64, 1, 1]).
2022-03-18 23:52:55 | WARNING | yolox.utils.checkpoint:24 - Shape of head.cls_preds.2.bias in checkpoint is torch.Size([80]), while shape of head.cls_preds.2.bias in model is torch.Size([1]).
2022-03-18 23:52:57 | WARNING | yolox.data.datasets.voc:143 -

You are using cached images in RAM to accelerate training.
This requires large system RAM.
Make sure you have 60G+ RAM and 19G available disk space for training VOC.

2022-03-18 23:52:57 | INFO | yolox.data.datasets.voc:154 - Caching images for the first time. This might take about 3 minutes for VOC
100%|#############################################################################| 1743/1743 [00:08<00:00, 215.56it/s]
2022-03-18 23:53:06 | INFO | yolox.data.datasets.voc:183 - Loading cached imgs...
2022-03-18 23:53:06 | ERROR | yolox.core.launch:98 - An error has been caught in function 'launch', process 'MainProcess' (6496), thread 'MainThread' (8588):
Traceback (most recent call last):

File "tools\train.py", line 132, in
launch(
└ <function launch at 0x000002AA12D21670>

File "d:\programdata\yolox\yolox\core\launch.py", line 98, in launch
main_func(*args)
│ └ (╒═══════════════════╤═══════════════════════════════════════════════════════════════════════════════════════════════════════...
└ <function main at 0x000002AA144790D0>

File "tools\train.py", line 117, in main
trainer.train()
│ └ <function Trainer.train at 0x000002AA137A8820>
└ <yolox.core.trainer.Trainer object at 0x000002AA1446C430>

File "d:\programdata\yolox\yolox\core\trainer.py", line 73, in train
self.before_train()
│ └ <function Trainer.before_train at 0x000002AA144783A0>
└ <yolox.core.trainer.Trainer object at 0x000002AA1446C430>

File "d:\programdata\yolox\yolox\core\trainer.py", line 148, in before_train
self.train_loader = self.exp.get_data_loader(
│ │ │ └ <function Exp.get_data_loader at 0x000002AA1448C280>
│ │ └ ╒═══════════════════╤════════════════════════════════════════════════════════════════════════════════════════════════════════...
│ └ <yolox.core.trainer.Trainer object at 0x000002AA1446C430>
└ <yolox.core.trainer.Trainer object at 0x000002AA1446C430>

File "D:\ProgramData\YOLOX\exps/example/yolox_voc\yolox_voc_nano.py", line 90, in get_data_loader
perspective=self.perspective,
└ ╒═══════════════════╤════════════════════════════════════════════════════════════════════════════════════════════════════════...

AttributeError: 'Exp' object has no attribute 'perspective'

Start with exps/example/yolox_voc/yolox_voc_nano.py at line 90, where get_data_loader accesses perspective, then inspect the Exp definition and related experiment files for the corresponding setting. Re-run the reported tools/train.py command after the change; done means data-loader creation proceeds without the AttributeError.