@@ -170,9 +170,11 @@ def _dump_registry(cls, file=None):
         """Debug helper to print the ABC registry."""
         print("Class: %s.%s" % (cls.__module__, cls.__qualname__), file=file)
         print("Inv.counter: %s" % ABCMeta._abc_invalidation_counter, file=file)
-        for name in sorted(cls.__dict__.keys()):
+        for name in sorted(cls.__dict__):
             if name.startswith("_abc_"):
                 value = getattr(cls, name)
+                if isinstance(value, WeakSet):
+                    value = set(value)
                 print("%s: %r" % (name, value), file=file)
 
     def __instancecheck__(cls, instance):
 
@@ -0,0 +1 @@
+Improve ABCMeta._dump_registry() output readability
Original file line number	Diff line number	Diff line change
@@ -0,0 +1 @@
	1	+ Improve ABCMeta._dump_registry() output readability