When I meet circular build deps: 1. Just get sources and try to build, satisfying what possible. Some deps required for docs or tests and may be ignored for the first time.
2. If a build dep is really required to build (I remember x11-utils), I install it separately from sources into /usr/local 3. And finally, if nothing helps, I make a dummy package :-) I remember gtk3 <-> gsettings-backend
