[components manager] when a component is registered again: warn -> debug

src/diffusers/modular_pipelines/components_manager.py

@@ -411,7 +411,9 @@ def add(self, name: str, component: Any, collection: str | None = None):
             if comp == component:
                 comp_name = self._id_to_name(comp_id)
                 if comp_name == name:
-                    logger.warning(f"ComponentsManager: component '{name}' already exists as '{comp_id}'")
+                    # The same object registered again under its name: a second pipeline sharing it, or a collection
+                    # it joins below. Nothing is duplicated, so this is not worth a warning.
+                    logger.debug(f"ComponentsManager: component '{name}' is already registered as '{comp_id}'")
                     component_id = comp_id
                     is_new_component = False
                     break
@@ -454,7 +456,7 @@ def add(self, name: str, component: Any, collection: str | None = None):
                 logger.info(
                     f"ComponentsManager: added component '{name}' in collection '{collection}': {component_id}"
                 )
-        else:
+        elif is_new_component:
             logger.info(f"ComponentsManager: added component '{name}' as '{component_id}'")
 
         if self._auto_offload_enabled and is_new_component:

tests/modular_pipelines/test_components_manager.py

@@ -218,6 +218,15 @@ def test_add_same_component_twice_reuses_id(self):
         assert first_id == second_id
         assert len(cm.components) == 1
 
+    def test_add_same_component_to_second_collection(self):
+        cm = ComponentsManager()
+        model = self.get_dummy_model()
+        first_id = cm.add("unet", model, collection="first")
+        second_id = cm.add("unet", model, collection="second")
+        assert first_id == second_id
+        assert len(cm.components) == 1
+        assert cm.collections["first"] == cm.collections["second"] == {first_id}
+
     def test_remove(self):
         cm = ComponentsManager()
         component_id = cm.add("unet", self.get_dummy_model())