Airblader [1] filed a deletion request for xcb-util-xrm-git [2]: xcb-util-xrm has hit the community packages a long time ago, and there isn't really active development anymore since it's stable, so the AUR package isn't really needed.
[1] https://aur.archlinux.org/account/Airblader/ [2] https://aur.archlinux.org/pkgbase/xcb-util-xrm-git/
