sys.argv cannot be set until sys exists.  As I mentioned above, subsequent calls before finalization must continue to be no-ops.

Code that depends on a bug, in this case of sys.argv not existing, is always vulnerable.  In this case, I would expect that people who want sys.argv to have a particular value would unconditionally set it.  If it were conditionally set, the program would likely exit or otherwise fail a test.  I intentionally have not suggested backporting a code change.