Re: git archive setting user and group

From: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Date: Jan 23, 2021, 05:16 UTC
Message-ID: <20210123051626.7hubdcda74gq3oxo@chatter.i7.local>
In-Reply-To: <YAus63jWBP1fIAhf@coredump.intra.peff.net>

On Fri, Jan 22, 2021 at 11:58:19PM -0500, Jeff King wrote:

> We also rely on system gzip. That's pretty stable, but I have heard tell
> that even `gzip -n` may differ on platforms.

The signatures are made against uncompressed .tar output, so this is not a consideration.

> Another fun one I saw recently: using export-subst with $Format:%h$ will
> produce different results depending on how many objects are present in
> the repository running git-archive.

As long as the output is the same with thhe flags we specified in the comment, we're still okay. E.g.:

    -----BEGIN PGP SIGNATURE-----
    Comment: This signature is for the .tar version of the archive
    Comment: git archive --format tar --prefix=linux-5.10.9/ v5.10.9
    Comment: git version 2.30.0

If running "git archive --format tar --prefix=linux-5.10.9/ v5.10.9" becomes non-deterministic within the same version of git, *then* I'm in trouble. It's been remarkably stable within the past 8 years, so I don't expect there's a dramatic reason why "--format tar" output would need to change -- it's not like the tar spec is much of a moving target.

-K