diff -r 5563f895b215 Lib/distutils/sysconfig.py
--- a/Lib/distutils/sysconfig.py	Fri Jul 04 17:00:25 2014 -0700
+++ b/Lib/distutils/sysconfig.py	Sat Jul 05 09:44:09 2014 -0700
@@ -165,7 +165,7 @@
             # version and build tools may not support the same set
             # of CPU architectures for universal builds.
             global _config_vars
-            if not _config_vars.get('CUSTOMIZED_OSX_COMPILER', ''):
+            if not get_config_var('CUSTOMIZED_OSX_COMPILER'):
                 import _osx_support
                 _osx_support.customize_compiler(_config_vars)
                 _config_vars['CUSTOMIZED_OSX_COMPILER'] = 'True'