MarsSeed [1] filed a deletion request for activityfox-git [2]: Obsolete package; does not work with KDE Plasma 6. Neither does the fork mentioned in AUR comment.
Upstream is EOL since 2018 [a]; the fork is abandoned since 2020 [b]. [a]: https://github.com/LeonidKalichkin/activityfox [b]: https://github.com/YuraT/activityfox [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/activityfox-git/
