I know this used to work. I must have broken it at some point. Manually
verified for HEAD and a real tag.
Also fix some logging so it is less chatty by default.
v2.0.2
I wanted to understand it all so I ran a bunch of tests and found that it was
resyncing when not required any time the rev was not == HEAD. Some
stackoverflow and git manpage spelunking produced this. Nice side-effect is
tha the workdir is named after the githash instead of random.