Fix for issue with APF packaging with multiple roles

Differential Revision: D69279705

Pull Request resolved: #1006

Author: andywag

torchx/specs/api.py

@@ -398,7 +398,7 @@ def __getattribute__(self, attrname: str) -> Any:
             else:
                 result = ov[attrname]()
             setattr(self, attrname, result)
-            del ov[attrname]
+            ov[attrname] = lambda: result
         return super().__getattribute__(attrname)
 
     def pre_proc(