On 2021-03-01 at 18:15:29, Junio C Hamano wrote:

"brian m. carlson" [off-list ref] writes:

quoted

  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.

quoted

  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