title: How can I check the loss when training RoBERTa in huggingface/transformers?
body: <p>I trained a RoBERTa model from scratch using <code>transformers</code>, but I can't check the training loss during training using</p>
  <p><a href="https://colab.research.google.com/github/huggingface/blog/blob/master/notebooks/01_how_to_train.ipynb" rel="nofollow noreferrer">https://colab.research.google.com/github/huggingface/blog/blob/master/notebooks/01_how_to_train.ipynb</a></p>
  <p>In the notebook, loss is printed every 500 steps, but there is no training loss logged during training:</p>
  <pre><code>Iteration: 100%|█████████▉| 20703/20711 [4:42:54&lt;00:07,  1.14it/s][A  
  Iteration: 100%|█████████▉| 20704/20711 [4:42:54&lt;00:05,  1.24it/s][A  
  Iteration: 100%|█████████▉| 20705/20711 [4:42:55&lt;00:05,  1.20it/s][A  
  Iteration: 100%|█████████▉| 20706/20711 [4:42:56&lt;00:04,  1.18it/s][A  
  Iteration: 100%|█████████▉| 20707/20711 [4:42:57&lt;00:03,  1.19it/s][A  
  Iteration: 100%|█████████▉| 20708/20711 [4:42:58&lt;00:02,  1.16it/s][A  
  Iteration: 100%|█████████▉| 20709/20711 [4:42:59&lt;00:01,  1.14it/s][A  
  Iteration: 100%|█████████▉| 20710/20711 [4:43:00&lt;00:00,  1.13it/s][A  
  Iteration: 100%|██████████| 20711/20711 [4:43:00&lt;00:00,  1.45it/s][A  
  Iteration: 100%|██████████| 20711/20711 [4:43:00&lt;00:00,  1.22it/s]  
  Epoch: 100%|██████████| 13/13 [61:14:16&lt;00:00, 16952.06s/it]  
  Epoch: 100%|██████████| 13/13 [61:14:16&lt;00:00, 16958.16s/it]
  
  compress roberta.20200717.zip on ./pretrained
  save roberta.20200717.zip on minio(petcharts)
  </code></pre>
  <p>No values are printed for the loss, so I don't know if the training converged well or not. How can I monitor the loss during training?</p>