setup.py commands not found about beeware.github.io HOT 2 CLOSED

im using archlinux, i have create an new rootfs an install everything inside that rootfs, i tried with venv too and does not work, say same errors

from beeware.github.io.

After you ran briefcase new, you received an error message "Template does not support 3.9".

That's the cause of the problem. Briefcase requires binary components, and we haven't prepared those components for Python 3.9. If you use Python 3.8 or earlier, you won't get that error.

The subsequent error about "setup.py not found" is an error of usage; you've cloned an old version of the template, which didn't support Android.

from beeware.github.io.