I'm currently trying to adapt my AUR packages to the new PEP 517 based build workflow . Some users of the telegram-tg  package reported after I changed it to PEP 517, that they are missing the actual python files in the final package. I investigated a bit further and found out if I build with makechrootpkg (like I usually do) the files are inside the package (that's why I didn't notice), but if I use yay for example (which uses makepkg without a clean chroot), the package does not contain the files. Now I'm a bit confused and don't know how to debug this further, could somebody please help me or at least give me a hint?
Thanks in advance j.r