I've been getting this error for over a week now. Haven't found a bug in b.f.o or b.g.o.
# emerge world -uDNav --with-bdeps=y These are the packages that would be merged, in order: Calculating dependencies... done! emerge: there are no ebuilds to satisfy ">=media-libs/gstreamer-1.10.5:1.0[introspection]". (dependency required by "dev-python/gst-python-1.10.5::gentoo" [ebuild]) (dependency required by "app-accessibility/orca-3.20.3-r1::gentoo" [installed]) (dependency required by "gnome-base/gnome-3.20-r1::gentoo[accessibility]" [installed]) (dependency required by "@selected" [set]) (dependency required by "@world" [argument])