runtimeError: cannot perform reduction function min on tensor with no elements because the operation does not have an identity about fcos

[caffelearn]

@tianzhi0549 ，it is solved,thanks

[tianzhi0549]

@caffelearn It seems that reg_targets_per_im has no elements.

[ZhengMengbin]

How did you solve it? I trained on other datasets and I also encountered this problem：
Traceback (most recent call last):
File "tools/train_net.py", line 198, in
main()
File "tools/train_net.py", line 190, in main
model = train(cfg, args.local_rank, args.distributed)
File "tools/train_net.py", line 77, in train
arguments,
File "/home/zhengchenbin/FcosNet/FCOS/maskrcnn_benchmark/engine/trainer.py", line 66, in do_train
loss_dict = model(images, targets)
File "/home/zhengchenbin/anaconda3/envs/FCOS/lib/python3.7/site-packages/torch/nn/modules/module.py", line 489, in call
result = self.forward(*input, **kwargs)
File "/home/zhengchenbin/anaconda3/envs/FCOS/lib/python3.7/site-packages/torch/nn/parallel/distributed.py", line 357, in forward
return self.module(*inputs[0], **kwargs[0])
File "/home/zhengchenbin/anaconda3/envs/FCOS/lib/python3.7/site-packages/torch/nn/modules/module.py", line 489, in call
result = self.forward(*input, **kwargs)
File "/home/zhengchenbin/FcosNet/FCOS/maskrcnn_benchmark/modeling/detector/generalized_rcnn.py", line 50, in forward
proposals, proposal_losses = self.rpn(images, features, targets)
File "/home/zhengchenbin/anaconda3/envs/FCOS/lib/python3.7/site-packages/torch/nn/modules/module.py", line 489, in call
result = self.forward(*input, **kwargs)
File "/home/zhengchenbin/FcosNet/FCOS/maskrcnn_benchmark/modeling/rpn/fcos/fcos.py", line 134, in forward
centerness, targets
File "/home/zhengchenbin/FcosNet/FCOS/maskrcnn_benchmark/modeling/rpn/fcos/fcos.py", line 144, in _forward_train
locations, box_cls, box_regression, centerness, targets
File "/home/zhengchenbin/FcosNet/FCOS/maskrcnn_benchmark/modeling/rpn/fcos/loss.py", line 146, in call
labels, reg_targets = self.prepare_targets(locations, targets)
File "/home/zhengchenbin/FcosNet/FCOS/maskrcnn_benchmark/modeling/rpn/fcos/loss.py", line 57, in prepare_targets
points_all_level, targets, expanded_object_sizes_of_interest
File "/home/zhengchenbin/FcosNet/FCOS/maskrcnn_benchmark/modeling/rpn/fcos/loss.py", line 98, in compute_targets_for_locations
is_in_boxes = reg_targets_per_im.min(dim=2)[0] > 0
RuntimeError: cannot perform reduction function min on tensor with no elements because the operation does not have an identity