@@ -74,11 +74,12 @@ class _RequireAttrsABCMeta(abc.ABCMeta):

     def __call__(self, *args, **kwargs):

         obj = super().__call__(*args, **kwargs)

         for name, type_ in obj.__annotations__.items():

-            if not hasattr(obj, name):

-                raise ValueError(f"Required attribute {name} not set in __init__.")

-            elif not isinstance(getattr(obj, name), type_):

-                raise TypeError(

-                    f"The attribute '{name}' is of {type_} instead of {type(getattr(obj, name))}"

-                )

-

+            try:

+                x = getattr(obj, name)

+                if not isinstance(x, type_):

+                    raise TypeError(

+                        f"The attribute '{name}' is of {type_} instead of {type(x)}."

+                    )

+            except AttributeError as e:

+                raise e(f"Required attribute {name} not set in __init__.")

         return obj