Traceback (most recent call last):


 "/usr/lib/python3.6/site-packages/twisted/internet/defer.py", line 150, in maybeDeferred

result = f(*args, **kw)


 "/usr/lib/python3.6/site-packages/pydispatch/robustapply.py", line 55, in robustApply

return receiver(*arguments, **named)


 "/usr/lib/python3.6/site-packages/scrapy/extensions/feedexport.py", line 217, in item_scraped

slot = self.slot
AttributeError: 'FeedExporter' object has no attribute 'slot'

Traceback (most recent call last):


 "train.py", line 330, in <module>

main(params)


 "train.py", line 290, in main

trainer.mt_step(lang, lang, params.lambda_ae)


 "/workspace/XLM/src/trainer.py", line 821, in mt_step

self.optimize(loss, ['encoder', 'decoder'])


 "/workspace/XLM/src/trainer.py", line 131, in optimize

loss.backward()


 "/opt/conda/lib/python3.6/site-packages/torch/tensor.py", line 96, in backward

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


 "/opt/conda/lib/python3.6/site-packages/torch/autograd/__init__.py", line 90, in backward

allow_unreachable=True)
# allow_unreachable flag


 "/opt/conda/lib/python3.6/site-packages/torch/nn/parallel/distributed.py", line 314, in distributed_data_parallel_hook

self._queue_reduction(bucket_idx)


 "/opt/conda/lib/python3.6/site-packages/torch/nn/parallel/distributed.py", line 344, in _queue_reduction

dev_grads_batch_coalesced = _flatten_dense_tensors(dev_grads_batch)


 "/opt/conda/lib/python3.6/site-packages/torch/_utils.py", line 151, in _flatten_dense_tensors

flat = torch.cat([t.contiguous().view(-1) for t in tensors], dim=0)


 "/opt/conda/lib/python3.6/site-packages/torch/_utils.py", line 151, in <listcomp>

flat = torch.cat([t.contiguous().view(-1) for t in tensors], dim=0)
AttributeError: 'NoneType' object has no attribute 'contiguous'
