Re: [PATCH] describe: count the distance correctly when commit dates are skewed

[Junio C Hamano <gitster@pobox.com>]

Patrick Steinhardt <ps@pks.im> writes:

>> I suspect that is just *way* too expensive in the bad case, but I
>> would hope/assume that any big repo already has generation numbers in
>> it, so maybe it doesn't matter.
>
> We nowadays generate commit graphs by default, yes. So usually
> repositories should have one, but there will of course be outliers where
> they don't exist because of whatever reason.

FWIW, one (out of two) tests that are expected to fail in
t6120-describe.sh started failing in the feature-testbed CI job
started failing.  I think GIT_TEST_COMMIT_GRAPH is the culprit.

> An alternative that might be worth considering here is to instead make
> users opt-out with "--no-exact", and then make that discoverable by
> emitting a warning in the case where we don't have a commit graph in the
> repository.

That would work as an escape hatch.  Sounds like a good plan.