xfailing test for deepcopying

Author: TomNicholas

datatree/tests/test_datatree.py

@@ -243,6 +243,7 @@ def test_copy(self):
                 assert "foo" not in node.attrs
                 assert node.attrs["Test"] is copied_node.attrs["Test"]
 
+    @pytest.mark.xfail(reason="unresolved bug with deepcopying")
     def test_deepcopy(self):
         dt = create_test_datatree()