ValueError: too many values to unpack (expected 3)

2021-11-11 22:08:07 | ERROR | yolox.core.launch:100 - An error has been caught in function 'launch', process 'MainProcess' (46556), thread 'MainThread' (139985019922176):
Traceback (most recent call last):

File "tools/train.py", line 132, in
args=(exp, args),
│ └ Namespace(batch_size=2, cache=True, ckpt='weights/yolox_l.pth', devices=0, dist_backend='nccl', dist_url=None, exp_file='exps...
└ ╒══════════════════╤═════════════════════════════════════════════════════════════════════════════════════════════════════════...

File "/home/zhaolimin/YOLOX/yolox/core/launch.py", line 100, in launch
main_func(*args)
│ └ (╒══════════════════╤════════════════════════════════════════════════════════════════════════════════════════════════════════...
└ <function main at 0x7f4ffcbf4268>

File "tools/train.py", line 110, in main
trainer.train()
│ └ <function Trainer.train at 0x7f4ffee5d6a8>
└ <yolox.core.trainer.Trainer object at 0x7f4ffcbf9e48>

File "/home/zhaolimin/YOLOX/yolox/core/trainer.py", line 72, in train
self.train_in_epoch()
│ └ <function Trainer.train_in_epoch at 0x7f4ffce72598>
└ <yolox.core.trainer.Trainer object at 0x7f4ffcbf9e48>

File "/home/zhaolimin/YOLOX/yolox/core/trainer.py", line 82, in train_in_epoch
self.after_epoch()
│ └ <function Trainer.after_epoch at 0x7f4ffce7be18>
└ <yolox.core.trainer.Trainer object at 0x7f4ffcbf9e48>

File "/home/zhaolimin/YOLOX/yolox/core/trainer.py", line 207, in after_epoch
self.evaluate_and_save_model()
│ └ <function Trainer.evaluate_and_save_model at 0x7f4ffcbd0158>
└ <yolox.core.trainer.Trainer object at 0x7f4ffcbf9e48>

File "/home/zhaolimin/YOLOX/yolox/core/trainer.py", line 304, in evaluate_and_save_model
evalmodel, self.evaluator, self.is_distributed
│ │ │ │ └ False
│ │ │ └ <yolox.core.trainer.Trainer object at 0x7f4ffcbf9e48>
│ │ └ <yolox.evaluators.coco_evaluator.COCOEvaluator object at 0x7f506e874630>
│ └ <yolox.core.trainer.Trainer object at 0x7f4ffcbf9e48>
└ YOLOX(
(backbone): YOLOPAFPN(
(backbone): CSPDarknet(
(stem): Focus(
(conv): BaseConv(
(conv): ...

ValueError: too many values to unpack (expected 3)

Start with the traceback path from tools/train.py through yolox/core/launch.py and yolox/core/trainer.py, especially evaluate_and_save_model in trainer.py. Inspect the COCO evaluation call and yolox/evaluators/coco_evaluator.py to locate the unpacking failure, then reproduce the reported training flow. Done means evaluation completes without the ValueError.