As of #13171 Gitian uses Bionic to build the binaries, but the host machine that runs this doesn't have to be Gitian. The instructions currently recommend Debian 9.

This machine-inside-a-machine situation is confusing enough, so all things equal I think it would be better to switch the recommended host to Bionic.

Windows build uses Bionic as well, per #13246. So everyone who does that, could potentially help out with Gitian builds. It would also allow us to reuse the nicely detailed Gitian instructions to help Windows folks out.

Last time I tried I ran into some trouble though. I'll try again for the v0.16.2 release candidate.