aaronfischer [1] filed a deletion request for bcusdk [2]:
This package is abandoned for years. eibd does not support ETS5 or
other standards, so it is basically useless.
A popular fork (knxd, AUR package: knxd-git) are in active development
for years.
This package just confuses newcomers which are searching for a tool to
access the KNX bus. It is safe to delete this package.
[1] https://aur.archlinux.org/account/aaronfischer/
[2] https://aur.archlinux.org/pkgbase/bcusdk/