Fixup

Matthias Koeppe · Matthias Koeppe · commit e3a541e03908 · 2021-10-02T17:17:24.000-07:00
diff --git a/src/sage/doctest/control.py b/src/sage/doctest/control.py
@@ -54,7 +54,7 @@
     pass
 
 from sage.features.sagemath import sage_optional_tags
-auto_optional_tags |= sage_optional_tags()
+auto_optional_tags.update(sage_optional_tags())
 
 class DocTestDefaults(SageObject):
     """
