Well, after several days of testing #yunohost
on a 4Gb, 6 core ARM v8 vps, , I've succesfully managed to install 1 - ONE - app.
I've a funny feeling their minimalist installation instructions are missing some very important steps, but I'm blowed if I can figure out (or even Google) what they might be.
Either that, or my host is using a pretty messed up version of Debian
Hell, I'm not even sure if Postgresql is part of the default installation!