MarsSeed [1] filed a deletion request for gtk3-git [2]: Not much maintained, badly packaged, and upstream is in minimal maintenance mode.
A new minor point release is published every time there is a bugfix, and Arch devs maintain the stable build in [extra] repo. Therefore I suggest to delete this superfluous package. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/gtk3-git/
