fix(tracker): guard init_trackers and log against None kwargs

src/accelerate/accelerator.py

@@ -3268,7 +3268,7 @@ def wait_for_everyone(self):
         wait_for_everyone()
 
     @on_main_process
-    def init_trackers(self, project_name: str, config: dict | None = None, init_kwargs: dict | None = {}):
+    def init_trackers(self, project_name: str, config: dict | None = None, init_kwargs: dict | None = None):
         """
         Initializes a run for all trackers stored in `self.log_with`, potentially with starting configurations
 
@@ -3297,6 +3297,8 @@ def init_trackers(self, project_name: str, config: dict | None = None, init_kwar
         ... )
         ```
         """
+        if init_kwargs is None:
+            init_kwargs = {}
         for tracker in self.log_with:
             if issubclass(type(tracker), GeneralTracker):
                 # Custom trackers are already initialized
@@ -3351,7 +3353,7 @@ def get_tracker(self, name: str, unwrap: bool = False):
         return GeneralTracker(_blank=True)
 
     @on_main_process
-    def log(self, values: dict, step: int | None = None, log_kwargs: dict | None = {}):
+    def log(self, values: dict, step: int | None = None, log_kwargs: dict | None = None):
         """
         Logs `values` to all stored trackers in `self.trackers` on the main process only.
 
@@ -3377,6 +3379,8 @@ def log(self, values: dict, step: int | None = None, log_kwargs: dict | None = {
         >>> accelerator.log({"loss": 0.5, "accuracy": 0.9})
         ```
         """
+        if log_kwargs is None:
+            log_kwargs = {}
         for tracker in self.trackers:
             tracker.log(values, step=step, **log_kwargs.get(tracker.name, {}))
 

tests/test_tracking.py

@@ -730,6 +730,24 @@ def test_log(self):
                 }
                 assert data == truth
 
+    def test_init_trackers_none_kwargs(self):
+        with tempfile.TemporaryDirectory() as d:
+            tracker = MyCustomTracker(d)
+            accelerator = Accelerator(log_with=tracker)
+            # Passing init_kwargs=None must not raise AttributeError
+            accelerator.init_trackers("Some name", init_kwargs=None)
+            accelerator.end_training()
+
+    def test_log_none_kwargs(self):
+        with tempfile.TemporaryDirectory() as d:
+            tracker = MyCustomTracker(d)
+            accelerator = Accelerator(log_with=tracker)
+            accelerator.init_trackers("Some name")
+            values = {"total_loss": 0.1}
+            # Passing log_kwargs=None must not raise AttributeError
+            accelerator.log(values, step=0, log_kwargs=None)
+            accelerator.end_training()
+
 
 @require_dvclive
 @mock.patch("dvclive.live.get_dvc_repo", return_value=None)