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:

> On Thu, Jun 2, 2016 at 1:06 PM, Lukas Fleischer <lfleischer@lfos.de> wrote:
> > On Thu, 02 Jun 2016 at 21:33:33, Junio C Hamano wrote:
> >> Lukas Fleischer <lfleischer@lfos.de> writes:
> >>
> >> > When running `git push`, it might occur that error messages are
> >> > transferred from the server to the client. While most messages (those
> >> > explicitly sent on sideband 2) are prefixed with "remote:", it seems
> >> > that error messages printed during the automatic householding performed
> >> > by git-gc(1) are displayed without any additional decoration. Thus, such
> >> > messages can easily be misinterpreted as git-gc failing locally, see [1]
> >> > for an actual example of where that happened.
> >>
> >> Sounds like a sensible goal to me.
> >
> > 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.

I think the implementation is doing much more, but it is probably a good
thing.

Right now we do not send auto-gc output over the sideband, and its
stderr goes to receive-pack's stderr. But that is a different place for
different protocols. For git-over-https, it is probably apache's error
log, or /dev/null if the server admin configured it. For ssh, it may be
back over the ssh stderr channel, or it may go to a log or nowhere if
the server admin intercepts receive-pack and redirects it.

So the greater question is not "should this output be marked" but
"should auto-gc data go over the sideband so that all clients see it
(and any server-side stderr does not)". And I think the answer is
probably yes. And that fixes the "remote: " thing as a side effect.

If it were no, then this is not the right solution, and the solution is
to swap out copy_to_sideband() for something that copies to stderr with
"remote: " prepended, or something.

-Peff