Fix deepcopy of _Sync fns and fix comparison in test_apply_func.

pytorch_lightning/trainer/connectors/logger_connector/result.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 from collections.abc import Generator
-from dataclasses import asdict, dataclass, replace
+from dataclasses import asdict, dataclass, fields, replace
 from functools import partial, wraps
 from typing import Any, Callable, Dict, List, Optional, Tuple, Union
 
@@ -74,6 +74,11 @@ def _generate_sync_fn(self) -> None:
         # ignore typing, bad support for `partial`: mypy/issues/1484
         self._fn: Callable = partial(fn, reduce_op=self.op, group=self.group)  # type: ignore [arg-type]
 
+    def __deepcopy__(self, memo: dict) -> "_Sync":
+        result = _Sync(**{field.name: getattr(self, field.name) for field in fields(self) if field.init})
+        memo[id(self)] = result
+        return result
+
     @property
     def __call__(self) -> Any:
         return self._fn

tests/utilities/test_apply_func.py

@@ -53,7 +53,10 @@ def __eq__(self, o: object) -> bool:
                 return NotImplemented
             else:
                 return (
-                    self.example_ids == o.example_ids and self.feature == o.feature and torch.equal(self.label, o.label)
+                    self.example_ids == o.example_ids
+                    and self.feature == o.feature
+                    and torch.equal(self.label, o.label)
+                    and self.some_constant == o.some_constant
                 )
 
     @dataclasses.dataclass