MarsSeed [1] filed a deletion request for orthcal-darkthemed [2]: Broken due to mixing Python2 & Python3 dependencies, and missing an already deleted perl library depend.
The upstream repo has not received any update for 4.5+ years. [a] [a]: https://gitlab.com/psposito/otrhcal [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/orthcal-darkthemed/