Created attachment 344278 [details] gnome-boxes-3.8.0.ebuild Gnome-boxes 3.6 uses old tracker. Attached ebuild for 3.8 (patch is submitted upstream - https://bugzilla.gnome.org/show_bug.cgi?id=697202).
Created attachment 352580 [details] gnome-boxes-3.8.3.ebuild
Looks like upstream has already included Maciej's patch. I'm attaching an ebuild for 3.8.3. It looks like vala is a hard requirement at least during ./configure because its looking for vapigen even when --disable-vala is passed. Perhaps that should be another upstream bug. Anyway, this installs fine, but I'm having trouble connecting to boxes. Might be due to missing dependencies - will look into it.