vocab_file and merges_file still required params for loading serialized tokenizers
e.g.

https://github.com/huggingface/transformers/blob/dd52804f5fce0a568ffbb3dc7fd088d2de0a0e56/src/transformers/models/gpt2/tokenization_gpt2_fast.py#L122-L132

Both of these should probably be optional params now. Setting `vocab_file` and `merges_file` to `None` while specifying a `tokenizer_file` works, but seems messy.
Indeed, we could do that, and then add a check below to ensure that we get a correct error message. Do you want to open a PR with the fix?<|||||>I wasn't planning on doing a PR because I wasn't sure of the scope of changes needed (e.g. every tokenizer `__init__` would need to be changed) and it also seems like there isn't any documentation for serialized tokenizers at all in `transformers`, so I assumed you were getting to that.<|||||>This issue has been automatically marked as stale and been closed because it has not had recent activity. Thank you for your contributions.

If you think this still needs to be addressed please comment on this thread.