Traceback (most recent call last):


 "/home/aclifton/ric-2020/textgen/run_finetune_gpt2.py", line 221, in <module>

testfinetune()


 "/home/aclifton/ric-2020/textgen/run_finetune_gpt2.py", line 215, in testfinetune

trainer.train()


 "/home/aclifton/anaconda3/lib/python3.7/site-packages/transformers/trainer.py", line 499, in train

tr_loss += self._training_step(model, inputs, optimizer)


 "/home/aclifton/anaconda3/lib/python3.7/site-packages/transformers/trainer.py", line 637, in _training_step

loss.backward()


 "/home/aclifton/anaconda3/lib/python3.7/site-packages/torch/tensor.py", line 198, in backward

torch.autograd.backward(self, gradient, retain_graph, create_graph)


 "/home/aclifton/anaconda3/lib/python3.7/site-packages/torch/autograd/__init__.py", line 100, in backward

allow_unreachable=True)
# allow_unreachable flag
RuntimeError: Trying to backward through the graph a second time, but the buffers have already been freed. Specify retain_graph=True when calling backward the first time.

Traceback (most recent call last):


 "sparrow-wifi.py", line 37, in <module>

from PyQt5.QtChart import QChart, QChartView, QLineSeries, QValueAxis
ModuleNotFoundError: No module named 'PyQt5.QtChart'
