Hi @NDugar,
You get the error below because the dataset you use for fine-tuning does not have a validation split. As you can see on the imdb dataset card this dataset has only the train, unsupervised and test splits available natively. You can either modify the dataset yourself to extract your own evaluation dataset or use the test split by replacing --do_eval  with --do_predict in your script.
I hope this helped you!
Error currently discussed:
Traceback (most recent call last):
  File "run_glue.py", line 568, in <module>
    main()
  File "run_glue.py", line 422, in main
    raise ValueError("--do_eval requires a validation dataset")
ValueError: --do_eval requires a validation dataset