[Enum] raise TypeError if super().__new__ called in custom __new__

Author: ethanfurman

Doc/howto/enum.rst

@@ -1353,6 +1353,13 @@ to handle any extra arguments::
     members; it is then replaced by Enum's :meth:`__new__` which is used after
     class creation for lookup of existing members.
 
+.. warning::
+
+    *Do not* call `super().__new__()`, as the lookup-only `__new__` is the one
+    that is found; instead, use the data type directly -- e.g.::
+   
+       obj = int.__new__(cls, value)
+
 
 OrderedEnum
 ^^^^^^^^^^^

Lib/enum.py

@@ -856,6 +856,8 @@ def _create_(cls, class_name, names, *, module=None, qualname=None, type=None, s
                 value = first_enum._generate_next_value_(name, start, count, last_values[:])
                 last_values.append(value)
                 names.append((name, value))
+        if names is None:
+            names = ()
 
         # Here, names is either an iterable of (name, value) or a mapping.
         for item in names:
@@ -1112,6 +1114,11 @@ def __new__(cls, value):
             for member in cls._member_map_.values():
                 if member._value_ == value:
                     return member
+        # still not found -- verify that members exist, in-case somebody got here mistakenly
+        # (such as via super when trying to override __new__)
+        if not cls._member_map_:
+            raise TypeError("%r has no members defined" % cls)
+        #
         # still not found -- try _missing_ hook
         try:
             exc = None