Traceback (most recent call last):


 "/home/.local/lib/python3.8/site-packages/detectron2/engine/train_loop.py", line 134, in train

self.run_step()


 "/home/.local/lib/python3.8/site-packages/detectron2/engine/defaults.py", line 423, in run_step

self._trainer.run_step()


 "/home/.local/lib/python3.8/site-packages/detectron2/engine/train_loop.py", line 228, in run_step

loss_dict = self.model(data)


 "/home/.local/lib/python3.8/site-packages/torch/nn/modules/module.py", line 727, in _call_impl

result = self.forward(*input, **kwargs)


 "/home/.local/lib/python3.8/site-packages/detectron2/modeling/meta_arch/panoptic_fpn.py", line 91, in forward

sem_seg_results, sem_seg_losses = self.sem_seg_head(features, gt_sem_seg)


 "/home/.local/lib/python3.8/site-packages/torch/nn/modules/module.py", line 727, in _call_impl

result = self.forward(*input, **kwargs)


 "/home/.local/lib/python3.8/site-packages/detectron2/modeling/meta_arch/semantic_seg.py", line 163, in forward

return None, self.losses(x, targets)


 "/home/.local/lib/python3.8/site-packages/detectron2/modeling/meta_arch/semantic_seg.py", line 183, in losses

loss = F.cross_entropy(


 "/home/.local/lib/python3.8/site-packages/torch/nn/functional.py", line 2468, in cross_entropy

return nll_loss(log_softmax(input, 1), target, weight, None, ignore_index, None, reduction)


 "/home/.local/lib/python3.8/site-packages/torch/nn/functional.py", line 2260, in nll_loss

if input.size(0) != target.size(0):
AttributeError: 'NoneType' object has no attribute 'size'

Traceback (most recent call last):


 "/home/and/Desktop/code/btgym/btgym/dataserver.py", line 134, in run

assert not self.dataset.data.empty
AttributeError: 'NoneType' object has no attribute 'empty'
