Remove extra_options

This is where main.options.python had been coming from.

build.py

@@ -277,11 +277,6 @@ def show_targets():
     """)
     sys.exit()
 
-extra_options = [
-        make_option('--python', action="store", dest="python", default="python"),
-        ]
-
-main( extra_options=extra_options
-    , default='show_targets'
+main( default='show_targets'
     , ignoreprefix="python"  # workaround for gh190
      )