Sorry for the spam, problems with internet connection. If the runtime dependency is missing, the following error occurs and catfish won't start: "Error: The required module gi.repository is missing." I recommend adding dev-python/pygobject:3 to RDEPEND. With this fixed, the following warning occurs: Warning: The optional module zeitgeist.client is missing. But that is only a minor thing and doesn't affect operation.
Fixed in 0.6.3