zoorat [1] filed a deletion request for serf-git [2]:

Broken PKGBUILD(incorrect url syntax), orphan, Last Updated: 2015-06-16 13:59. sadly @ryanmjacobs reported this in comments on 2020-04-10 05:21, but no one ever updated this package... and there is 'serf-cluster' package which is nearly up-to-date.

[1] https://aur.archlinux.org/account/zoorat/ [2] https://aur.archlinux.org/pkgbase/serf-git/