On first installation with USE="plugins", portage raises a circular dependency issue zeitgeist {R,}DEPEND -> zeitgeist-datasources {R,}DEPEND-> libzeitgiest -> RDEPEND zeitgeist zeitgeist-datasources has zeitgeist as PDEPEND already but I think the proper fix is to actually have zeitgeist-datasources as a PDEPEND in zeitgeist ebuild. According to https://devmanual.gentoo.org/general-concepts/dependencies/, this is probably the way it should be.
commit 39d65cb08a78474eeb6023a176086d8b985a9553 Author: Justin Lecher <jlec@gentoo.org> Date: Sun Oct 25 10:18:54 2015 +0100 gnome-extra/zeitgeist: Break circular dependency by moving gnome-extra/zeitgeist-datasources to PDEPEND Gentoo-Bug: https://bugs.gentoo.org/show_bug.cgi?id=563954 Package-Manager: portage-2.2.23 Signed-off-by: Justin Lecher <jlec@gentoo.org> https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=39d65cb08a78474eeb6023a176086d8b985a9553