uhh. __builtins__ is a module in __main__ and a dict elsewhere

diff --git a/Lib/doctest.py b/Lib/doctest.py
index 64a0375da31e2b4c68b9f49bc633a252c493c662..e2b595ea51fb89aa708480a1dff6d35254099987 100644 (file)
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -1360,7 +1360,10 @@ class DocTestRunner:
             linecache.getlines = self.save_linecache_getlines
             if clear_globs:
                 test.globs.clear()
-                __builtins__['_'] = None
+                if __name__ == "__main__":
+                    __builtins__._ = None
+                else:
+                    __builtins__['_'] = None
 
     #/////////////////////////////////////////////////////////////////
     # Summarization