Add error message concerning revision (#13266)

* add error message concerning revision

* Update src/transformers/configuration_utils.py

Co-authored-by: Lysandre Debut <lysandre@huggingface.co>

* re-add double line endings

* is not None instead of implicit bool casting

Co-authored-by: Lysandre Debut <lysandre@huggingface.co>

src/transformers/tokenization_utils_base.py

@@ -1723,6 +1723,10 @@ class PreTrainedTokenizerBase(SpecialTokensMixin, PushToHubMixin):
                 f"- '{pretrained_model_name_or_path}' is a correct model identifier listed on 'https://huggingface.co/models'\n\n"
                 f"- or '{pretrained_model_name_or_path}' is the correct path to a directory containing relevant tokenizer files\n\n"
             )
+
+            if revision is not None:
+                msg += f"- or '{revision}' is a valid git identifier (branch name, a tag name, or a commit id) that exists for this model name as listed on its model page on 'https://huggingface.co/models'\n\n"
+
             raise EnvironmentError(msg)
 
         for file_id, file_path in vocab_files.items():