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From: Junio C Hamano <gitster@pobox.com>
To: Derrick Stolee <stolee@gmail.com>
Cc: Jonathan Nieder <jrnieder@gmail.com>,
	Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>,
	git@vger.kernel.org, Derrick Stolee <derrickstolee@github.com>,
	Derrick Stolee <dstolee@microsoft.com>
Subject: Re: [PATCH] t1092: use GIT_PROGRESS_DELAY for consistent results
Date: Tue, 25 May 2021 11:41:04 +0900	[thread overview]
Message-ID: <xmqqa6ojilhb.fsf@gitster.g> (raw)
In-Reply-To: <e35b5217-362f-fc4f-7396-08218a9abf63@gmail.com> (Derrick Stolee's message of "Mon, 24 May 2021 16:38:18 -0400")

Derrick Stolee <stolee@gmail.com> writes:

> The test is comparing the same exact Git command just with
> different configurations. Any change to what Git writes to
> stderr should be consistent across these, unless there is
> an explicit reason why it would behave differently across
> these options (for example, saying "You are in a sparse
> checkout" in 'git status').
>
> There are no expectations that stderr is stable across
> versions of Git. These tests don't add friction to developers
> making new features or changing the error messages that appear
> over stderr. It's just that these tests should catch any
> unintended inconsistency across these modes.

If it just happens that an auto-gc gets triggered, and millions of
other similar reasons in the future, will break that expectation,
without running two different vintages of Git.

I agree with Jonathan that it fundamentally is flakey to expect two
invocations of Git will behave exactly the same.  Even repacking a
repository starting from exactly the same state into a single pack
may not produce byte-for-byte identical result due to thread
scheduling.

      parent reply	other threads:[~2021-05-25  2:41 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-24 19:55 [PATCH] t1092: use GIT_PROGRESS_DELAY for consistent results Derrick Stolee via GitGitGadget
2021-05-24 20:28 ` Jonathan Nieder
2021-05-24 20:38   ` Derrick Stolee
2021-05-24 21:42     ` Taylor Blau
2021-05-24 22:57       ` Ævar Arnfjörð Bjarmason
2021-05-25  0:13         ` Taylor Blau
2021-05-25  0:39           ` Derrick Stolee
2021-05-25  6:32             ` Junio C Hamano
2021-05-25 10:54               ` Derrick Stolee
2021-05-25 20:46                 ` Junio C Hamano
2021-05-25 21:14                   ` Junio C Hamano
2021-05-25 21:49                   ` Taylor Blau
2021-05-25  2:54           ` Junio C Hamano
2021-05-25 15:10             ` Taylor Blau
2021-05-25  7:39           ` Ævar Arnfjörð Bjarmason
2021-05-25  8:06             ` Junio C Hamano
2021-05-25  2:49       ` Junio C Hamano
2021-05-25  2:41     ` Junio C Hamano [this message]

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