Fix for issue 9164
diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index 50c8133..28731df 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -660,8 +660,7 @@
                 cflags = get_config_vars().get('CFLAGS')
 
                 archs = re.findall('-arch\s+(\S+)', cflags)
-                archs.sort()
-                archs = tuple(archs)
+                archs = tuple(sorted(set(archs)))
 
                 if len(archs) == 1:
                     machine = archs[0]