zoutiyx [1] filed a deletion request for adapta-gtk-theme-git [2]:

This package is out of date and due to the release cycle upstream, this package will continue to break since the dependancies vary for update to update. The PKGBUILD doesn't have dynamic capabilities to adapt to these changes and the maintainer doesn't look like he/she is up for updating. There is another package adapta-gtk-theme which does a great job at updating and adjusting to the changes upstream. The package is usually updated by the daily or atleast within 3 days of a new version upstream.

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