Re: [PATCH 1/2] pretty: add %(describe)

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

Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

> On Sun, Feb 14 2021, René Scharfe wrote:
>
>> Add a format placeholder for describe output.  Implement it by actually
>> calling git describe, which is simple and guarantees correctness.  It's
>> intended to be used with $Format:...$ in files with the attribute
>> export-subst and git archive. 
>
> Does it really guarantee correctness though? In "builtin/describe.c" we
> first walk over the refs and use that to format all N items we're asked
> about.
>
> Under "git log" this is presumably in a race where refs added/deleted
> during the run of "git log" will change the describe output to be
> inconsistent with earlier lines.

Yes, but it is not a news that the describe for a given commit will
not stay the constant while you add more objects to the repository
or you change the tags, whether the "describe" is driven internally
by "git log" or by the end-user, so I am not sure how that becomes
an issue.  If the output is inconsistent in a quiescent repository,
that would be a problem, though.

Puzzled.

Thanks.