diff -r 07ee48ce4513 Lib/distutils/core.py
--- a/Lib/distutils/core.py	Thu Sep 05 16:04:35 2013 +0200
+++ b/Lib/distutils/core.py	Sun Sep 08 12:01:44 2013 +0200
@@ -211,14 +211,13 @@
     _setup_stop_after = stop_after
 
     save_argv = sys.argv
-    g = {'__file__': script_name}
-    l = {}
+    g = {'__file__': script_name, '__name__': '__main__'}
     try:
         try:
             sys.argv[0] = script_name
             if script_args is not None:
                 sys.argv[1:] = script_args
-            exec open(script_name, 'r').read() in g, l
+            exec open(script_name, 'r').read() in g
         finally:
             sys.argv = save_argv
             _setup_stop_after = None
@@ -235,7 +234,7 @@
                "perhaps '%s' is not a Distutils setup script?") % \
               script_name
 
-    # I wonder if the setup script's namespace -- g and l -- would be of
+    # I wonder if the setup script's namespace -- g -- would be of
     # any interest to callers?
     #print "_setup_distribution:", _setup_distribution
     return _setup_distribution