RuntimeError: one of the variables needed for gradient computation has been modified by an inplace operation

[XinyiYang5]

Hi, when I ran coref.py file, I encountered a RuntimeError: one of the variables needed for gradient computation has been modified by an inplace operation. I've tried pytorch 0.4.1 in the requirements.txt and pytorch 1.0 but they got same error. Could you please look into this? Thanks!

File "coref.py", line 692, in
trainer.train(150)
File "coref.py", line 458, in train
self.train_epoch(epoch, *args, **kwargs)
File "coref.py", line 488, in train_epoch
corefs_found, total_corefs, corefs_chosen = self.train_doc(doc)
File "coref.py", line 555, in train_doc
loss.backward()
File "/opt/conda/envs/mlkit36/lib/python3.6/site-packages/torch/tensor.py", line 93, in backward
torch.autograd.backward(self, gradient, retain_graph, create_graph)
File "/opt/conda/envs/mlkit36/lib/python3.6/site-packages/torch/autograd/init.py", line 90, in backward
allow_unreachable=True) # allow_unreachable flag
RuntimeError: one of the variables needed for gradient computation has been modified by an inplace operation

[shayneobrien]

The inplace operation is defined here. I think I did it this way because in 0.4.1, dropout could only be applied to a packed sequence by first unpacking it, applying dropout, and then repacking it. This seems likely to have been fixed in pytorch 1.0...

[vaibkumr]

I was getting the exact same error for torch==1.1.0
Changing

self.emb_dropout = nn.Dropout(0.50, inplace=True)
self.lstm_dropout = nn.Dropout(0.20, inplace=True)

to

self.emb_dropout = nn.Dropout(0.50)
self.lstm_dropout = nn.Dropout(0.20)

fixed it. Just as written by the author above me.
Thank you.