diff -r b6059bac8a9c Lib/distutils/core.py
--- a/Lib/distutils/core.py	Fri Sep 06 15:41:30 2013 -0500
+++ b/Lib/distutils/core.py	Sat Sep 07 11:53:21 2013 +0200
@@ -207,15 +207,14 @@
     _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
             with open(script_name, 'rb') as f:
-                exec(f.read(), g, l)
+                exec(f.read(), g)
         finally:
             sys.argv = save_argv
             _setup_stop_after = None
@@ -231,7 +230,7 @@
                "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