Fix mypy errors: PyTreeSpec inheritance (#160652)

RohitRathore1 · pytorchmergebot · commit 114813ca77fe · 2025-08-16T05:14:11.000Z
Fixes #160650. I added type ignore comment to `LeafSpec` class inheritance in `torch/utils/_cxx_pytree.py` to handle `PyTreeSpec` being marked as final in optree's type stubs. Pull Request resolved: #160652 Approved by: https://github.com/Skylion007
diff --git a/torch/utils/_cxx_pytree.py b/torch/utils/_cxx_pytree.py
@@ -994,7 +994,7 @@ def __instancecheck__(self, instance: object) -> bool:
         return _is_pytreespec_instance(instance) and instance.is_leaf()
 
 
-class LeafSpec(TreeSpec, metaclass=LeafSpecMeta):
+class LeafSpec(TreeSpec, metaclass=LeafSpecMeta):  # type: ignore[misc,final]
     def __new__(cls) -> "LeafSpec":
         return optree.treespec_leaf(none_is_leaf=True)  # type: ignore[return-value]
 
