Error logging for git over ssh?

Diagnosing errors with git over ssh has historically required tooling up for debugging or looking at things from the client side, because git does not log anything on the server side.

It would be a boon to those running busy git servers to be able to diagnose by looking at a log. It can be both old-fashioned, or very modern (if you are using journald).

After digging around the mailing list, current git master and "what's cooking", I fail to see anything. Is there a built-in way in modern git to direct stderr on the server side to a logger or to a file? (I see git-daemon has some support, but it does not handle git ssh connections...)

Some common "use cases" I've had to debug the hard way:

 - a ref is not up to date and the server rejects non-FF pushes
 - perms issues over objects or refs
 - ENOSPC
 - refs have a stale .lock file

cheers,

m