Re: Mark remote `gc --auto` error messages

[Jeff King <peff@peff.net>]

On Thu, Jun 02, 2016 at 01:14:02PM -0700, Junio C Hamano wrote:

> > What exactly are you referring to (you only quoted the introduction)?
> > Do you think we should fix the git-gc issue but keep the general
> > behavior of printing messages unaltered? Do you think it would be
> > worthwhile to make server messages distinguishable in general?
> 
> The latter, which I think was what your implementation was attempting to do
> if I read it correctly.

And btw, I don't think this patch fixes the general case. E.g., if
receive-pack hits any of its die("BUG") lines, they will not be
prefixed. Most clients wouldn't see them, but ssh ones would.

To fix that you'd have to do a whole async process wrapping
`receive-pack` that just reads its stdout and stderr and muxes it back
over the sideband. But I can think of two roadblocks there:

  - I think the original design of receive-pack was _not_ to share all
    of stderr with the user, because it might contain secret-ish
    server-side things. That's why we have rp_error() which copies to
    the sideband.

    I don't know how useful that is in practice. We copy the stderr
    wholesale from sub-processes like index-pack, so things like file
    paths are likely to get leaked there.

  - the implementation is a bit tricky, because the die() will take
    down the mux thread, too.

-Peff