edh [1] filed a orphan request for gtk-theme-arc-git [2]:

No reaction to an inquiry concerning the naming schema dating back about half a year and further no reaction to a notification of an updated upstream location more than a month ago.

[1] https://aur.archlinux.org/account/edh/ [2] https://aur.archlinux.org/pkgbase/gtk-theme-arc-git/