Record the last __new__ lookup by class name instead of counting

Author: chaerrypick01

Lib/test/picklecommon.py

@@ -292,11 +292,13 @@ class MyIntWithNew2(MyIntWithNew):
 
 # For test_newobj_metaclass_lookup
 class LookupLoggingMeta(type):
-    new_lookup_count = 0
+    # Name of the last class whose __new__ was looked up through the
+    # metaclass.
+    last_new_lookup = None
 
     def __getattribute__(cls, name):
         if name == '__new__':
-            LookupLoggingMeta.new_lookup_count += 1
+            LookupLoggingMeta.last_new_lookup = cls.__name__
         return super().__getattribute__(name)
 
 class NewInheriting(metaclass=LookupLoggingMeta):

Lib/test/pickletester.py

@@ -3608,11 +3608,12 @@ def test_newobj_metaclass_lookup(self):
             for proto in protocols[min_proto:]:
                 with self.subTest(cls=cls, proto=proto):
                     s = self.dumps(cls(42), proto)
-                    before = LookupLoggingMeta.new_lookup_count
+                    LookupLoggingMeta.last_new_lookup = None
                     y = self.loads(s)
                     self.assertIs(type(y), cls)
                     self.assertEqual(y.value, 42)
-                    self.assertGreater(LookupLoggingMeta.new_lookup_count, before)
+                    self.assertEqual(LookupLoggingMeta.last_new_lookup,
+                                     cls.__name__)
 
     def test_newobj_not_class(self):
         # Issue 24552