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Re: [PATCH 4/4] docs: note that archives are not stable

From
brian m. carlson <sandals@crustytoothpaste.net>
Date
Mar 3, 2021, 00:36 UTC
Message-ID
<YD7aDwX/aiRN0GZs@camp.crustytoothpaste.net>
In-Reply-To
<xmqqpn0irb9a.fsf@gitster.c.googlers.com>
On 2021-03-01 at 18:15:29, Junio C Hamano wrote:
Show 23 quoted lines
> "brian m. carlson" <sandals@crustytoothpaste.net> writes:
> 
> >   The output of 'git archive' is guaranteed to be the same across
> >   versions of git, but the archive itself is not guaranteed to be
> >   bit-for-bit identical.
> 
> I do not quite get this; your original was clearer.  What does it
> mean to "be the same across versions of git but not identical" at
> the same time?  If output from Git version 1.0 and 2.0 are guranteed
> to be the same across versions, what more is there for the readers
> to worry about the format stability?
> 
> Perhaps you meant
> 
> 	... is guaranteed to be the same for any given version of
> 	Git across ports.
> 
> or something?  It would allow kernel.org's use of "Konstantin tells
> kernel.org users to use Git version X to run 'git archive' and
> create detached signature on the output, and upload only the
> signature.  The site uses the same Git version X to run 'git
> archive' to create a tarball and the detached signature magically
> matches, as the output on two places are bit-for-bit identical".

I think what I had intended was that Git produces deterministic output, but I don't actually think that's true across ports. If someone uses a different version of zlib on a different OS, the output may differ.

I'll rephrase to avoid giving a misleading impression.
Show 7 quoted lines
> >   The output of 'git archive' has changed
> >   in the past, and most likely will in the future.
> 
> That is correct as a statement of fact.  I feel that saying it is
> either redundant and insufficient at the same time.  If we want to
> tell them "do not depend on the output being bit-for-bit identical",
> we should say it more explicitly after this sentence, I would think.
I agree we should explicitly say that.
-- 
brian m. carlson (he/him or they/them)
Houston, Texas, US
Previous: Junio C HamanoNext: Junio C Hamano
Message 15 of 16 in “Documentation updates to FAQ and git-archive”
  1. 0/4 Documentation updates to FAQ and git-archivebrian m. carlson, Feb 27, 2021
  2. 3/4 docs: add a FAQ section on push and fetch problemsbrian m. carlson, Feb 27, 2021
  3. Ævar Arnfjörð BjarmasonFeb 28, 2021
  4. brian m. carlsonFeb 28, 2021
  5. Junio C HamanoMar 1, 2021
  6. 1/4 docs: add a question on syncing repositories to the FAQbrian m. carlson, Feb 27, 2021
  7. Ævar Arnfjörð BjarmasonFeb 28, 2021
  8. brian m. carlsonMar 15, 2021
  9. 2/4 docs: add line ending configuration article to FAQbrian m. carlson, Feb 27, 2021
  10. 4/4 docs: note that archives are not stablebrian m. carlson, Feb 27, 2021
  11. Ævar Arnfjörð BjarmasonFeb 28, 2021
  12. brian m. carlsonFeb 28, 2021
  13. Ævar Arnfjörð BjarmasonFeb 28, 2021
  14. Junio C HamanoMar 1, 2021
  15. brian m. carlsonMar 3, 2021
  16. Junio C HamanoMar 3, 2021

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