> Why use a shell script in the first place?

you can't run python for a cross build, unless you "tweak" the interpreter.  you can do that with a shell script only.  As suggested in the original issue/patch, I did propose to remove the python implementation, so a fix for the shell script seems to be the better approach.  Tweaking the CFLAGS in the shell script should be possible too.  Maybe you could describe what exactly needs tweaking, as I cannot find this in the python implementation either.