Same program - different names - one builds - the other fails

I have two identical programs, except for their name: sfalmanac and skyalmanac (both in PyPI). Historically, I once needed different program logic, which is no longer necessary. For a while I will maintain the two, then retire sfalmanac. Up to now I used setup.cfg and both builds worked flawlessly. I decided try the new method using only a pyproject.toml file. After a while I implemented a ‘src’ parent folder and figured the rest out. Both programs are identical in logic and structure. I bui...