Using torch (1.1.0), flair (0.4.2) [1], I get the following error when I try to train a model.
  File "/home/foobar/github/cbd/venv/lib/python3.6/site-packages/torch/nn/modules/rnn.py", line 204, in forward
    _impl = _rnn_impls[self.mode]
KeyError: 'GRU'

Python interpeter
>>> import torch
>>> torch.version.cuda
'10.0.130'
>>> torch.cuda.is_available()
True

My understanding is a bit shaky. Should the version of nvcc compilation tools align with torch's cuda version? It doesn’t, but as you can see above, cuda is still available.
If there’s anything I’ve missed that might help diagnosing, please say.
Shell
$ nvcc --version
nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2017 NVIDIA Corporation
Built on Fri_Nov__3_21:07:56_CDT_2017
Cuda compilation tools, release 9.1, V9.1.85

[1] Flair NLP – https://github.com/zalandoresearch/flair 2
Full error
2019-08-12 17:49:33,828 Reading data from /home/foobar/tmp/splits
2019-08-12 17:49:33,828 Train: /home/foobar/tmp/splits/train.txt
2019-08-12 17:49:33,828 Dev: /home/foobar/tmp/splits/dev.txt
2019-08-12 17:49:33,828 Test: /home/foobar/tmp/splits/test.txt
2019-08-12 17:59:10,064 {'noncb', 'cb'}
2019-08-12 18:08:17,296 ----------------------------------------------------------------------------------------------------
2019-08-12 18:08:17,296 Evaluation method: MICRO_F1_SCORE
Traceback (most recent call last):
  File "/home/foobar/github/cbd/venv/bin/cbd-train", line 11, in <module>
    load_entry_point('cbd', 'console_scripts', 'cbd-train')()
  File "/home/foobar/github/cbd/cb/train.py", line 50, in train
    max_epochs=150)
  File "/home/foobar/github/cbd/venv/lib/python3.6/site-packages/flair/trainers/trainer.py", line 93, in train
    embeddings_in_memory,
  File "/home/foobar/github/cbd/venv/lib/python3.6/site-packages/flair/models/text_classification_model.py", line 177, in evaluate
    labels, loss = self.forward_labels_and_loss(batch)
  File "/home/foobar/github/cbd/venv/lib/python3.6/site-packages/flair/models/text_classification_model.py", line 108, in forward_labels_and_loss
    scores = self.forward(sentences)
  File "/home/foobar/github/cbd/venv/lib/python3.6/site-packages/flair/models/text_classification_model.py", line 70, in forward
    self.document_embeddings.embed(sentences)
  File "/home/foobar/github/cbd/venv/lib/python3.6/site-packages/flair/embeddings.py", line 2081, in embed
    rnn_out, hidden = self.rnn(packed)
  File "/home/foobar/github/cbd/venv/lib/python3.6/site-packages/torch/nn/modules/module.py", line 547, in __call__
    result = self.forward(*input, **kwargs)
  File "/home/foobar/github/cbd/venv/lib/python3.6/site-packages/torch/nn/modules/rnn.py", line 204, in forward
    _impl = _rnn_impls[self.mode]
KeyError: 'GRU'