There are actually 3 attributes that may be absent when CPython itself isn't managing the C level entry point: sys.argv, sys.warnoptions, and sys._xoptions.

I'd be more inclined to make the implementation match the docs though, and have these all be empty lists in the not-configured case, rather than absent entirely. (Accessing sys.argv[0] would still be an error in that situation, just an IndexError instead of an AttributeError)