Ok, so the Android build is failing...

python-for-android needs pep517<0.7.0, see
https://github.com/kivy/python-for-android/blob/f4a91b06e24ce9f137b996e5eff5f319b9a6ae80/setup.py#L25
which needs flit
https://github.com/pypa/pep517/blob/3d4f9d76408bedf152a66932126f4dcf20fc121d/pyproject.toml#L2

Notice that new pep517 depends on flit_core, which we already depend on,
but old pep517 depends on flit, which is a larger package.
pypa/pyproject-hooks@8bdb4ef

We could add flit into base-base.txt, but ideally p4a would just use newer pep517.

I've opened a PR for p4a:
kivy/python-for-android#2680