run_rnn_agent.py run error

[futurepaycc]

torch: 1.8.0+cu111
python: 3.7.7

log:

File "run_rnn_agent.py", line 82, in
loss.backward(retain_graph=True)
File "/home/liunix/.pyenv/versions/3.7.7/lib/python3.7/site-packages/torch/tensor.py", line 245, in backward
torch.autograd.backward(self, gradient, retain_graph, create_graph, inputs=inputs)
File "/home/liunix/.pyenv/versions/3.7.7/lib/python3.7/site-packages/torch/autograd/init.py", line 147, in backward
allow_unreachable=True, accumulate_grad=True) # allow_unreachable flag
RuntimeError: one of the variables needed for gradient computation has been modified by an inplace operation: [torch.FloatTensor [4, 16]], which is output 0 of TBackward, is at version 3; expected version 2 instead. Hint: enable anomaly detection to find the operation that failed to compute its gradient, with torch.autograd.set_detect_anomaly(True)