Fix W&B run name (#30462)

* Remove comparison to output_dir

* Update docs for `run_name`

* Add warning

src/transformers/integrations/integration_utils.py

@@ -762,9 +762,14 @@ class WandbCallback(TrainerCallback):
             if trial_name is not None:
                 init_args["name"] = trial_name
                 init_args["group"] = args.run_name
-            else:
-                if not (args.run_name is None or args.run_name == args.output_dir):
-                    init_args["name"] = args.run_name
+            elif args.run_name is not None:
+                init_args["name"] = args.run_name
+                if args.run_name == args.output_dir:
+                    self._wandb.termwarn(
+                        "The `run_name` is currently set to the same value as `TrainingArguments.output_dir`. If this was "
+                        "not intended, please specify a different run name by setting the `TrainingArguments.run_name` parameter.",
+                        repeat=False,
+                    )
 
             if self._wandb.run is None:
                 self._wandb.init(

src/transformers/training_args.py

@@ -420,9 +420,9 @@ class TrainingArguments:
             the past hidden states for their predictions. If this argument is set to a positive int, the `Trainer` will
             use the corresponding output (usually index 2) as the past state and feed it to the model at the next
             training step under the keyword argument `mems`.
-        run_name (`str`, *optional*):
+        run_name (`str`, *optional*, defaults to `output_dir`):
             A descriptor for the run. Typically used for [wandb](https://www.wandb.com/) and
-            [mlflow](https://www.mlflow.org/) logging.
+            [mlflow](https://www.mlflow.org/) logging. If not specified, will be the same as `output_dir`.
         disable_tqdm (`bool`, *optional*):
             Whether or not to disable the tqdm progress bars and table of metrics produced by
             [`~notebook.NotebookTrainingTracker`] in Jupyter Notebooks. Will default to `True` if the logging level is