Re: [External] Git Rebase: test failing with GIT_TEST_STASH_USE_BUILTIN=false

From: Son Luong Ngoc <sluongng@gmail.com>
To: Son Luong Ngoc <son.luong@booking.com>
Cc: Junio C Hamano <gitster@pobox.com>,
	git@vger.kernel.org,
	Johannes Schindelin <johannes.schindelin@gmx.de>,
	Thomas Gummerer <t.gummerer@gmail.com>,
	Paul-Sebastian Ungureanu <ungureanupaulsebastian@gmail.com>,
	Son Luong Ngoc <sluongng@gmail.com>
Subject: Re: [External] Git Rebase: test failing with GIT_TEST_STASH_USE_BUILTIN=false
Date: Sun, 1 Mar 2020 10:59:03 +0100	[thread overview]
Message-ID: <89C2FD92-5616-4834-98ED-22630DA61925@gmail.com> (raw)
In-Reply-To: <710DB9BA-D134-48E7-8CAB-B8816FED8AB8@booking.com>

(this is a resent due to git@vger.kernel.org blocked HTML content, sry for the noises)
(following up on https://public-inbox.org/git/xmqq36ayob9a.fsf@gitster-ct.c.googlers.com/T/#t )

Hi folks,

I ran a simple git-bisect on this to try to figure-out whats wrong:

$ cat run-test.sh
#!/bin/bash

make -j8 prefix=/usr all
(
  cd ./t
  GIT_TEST_STASH_USE_BUILTIN=false ./t3903-stash.sh --run='103'
)
$ git bisect start master v2.22.2
$ git bisect run ./run-test.sh
...
$ git bisect log
(b932f6a5e8...)|BISECTING ~/work/booking/git/git> git bisect log
# bad: [2d2118b814c11f509e1aa76cb07110f7231668dc] The seventh batch for 2.26
# good: [d9589d4051537c387b70dc76e430c61b4c85a86d] Git 2.22.2
git bisect start 'HEAD' 'v2.22.2'
# bad: [22dd22dce050f042b3eec165440966186691db42] Merge branch 'wb/fsmonitor-bitmap-fix'
git bisect bad 22dd22dce050f042b3eec165440966186691db42
# bad: [fa9e7934c780bc804a09bfc88a93825096b3155e] Merge branch 'bm/repository-layout-typofix'
git bisect bad fa9e7934c780bc804a09bfc88a93825096b3155e
# good: [3a94cb31d52f061c315b00bfc005f1b1c42ac92d] bin-wrappers: append `.exe` to target paths if necessary
git bisect good 3a94cb31d52f061c315b00bfc005f1b1c42ac92d
# bad: [7b70d46ca410f9d37045558329c3143570d47ba6] Merge branch 'bb/grep-pcre2-bug-message-fix'
git bisect bad 7b70d46ca410f9d37045558329c3143570d47ba6
# good: [d60dc1a0b3829f3c4d69696f43f1c178c0701cdb] Merge branch 'ew/repack-with-bitmaps-by-default'
git bisect good d60dc1a0b3829f3c4d69696f43f1c178c0701cdb
# good: [43ba21cb574ee3f9a1acf4580868982f4c883ac6] Merge branch 'tg/range-diff-output-update'
git bisect good 43ba21cb574ee3f9a1acf4580868982f4c883ac6
# good: [080af915a3ee4d9511dc288b29143b9958ac0adc] Merge branch 'mt/dir-iterator-updates'
git bisect good 080af915a3ee4d9511dc288b29143b9958ac0adc
# bad: [75ce48674889df6a2bb493fb5d6bef0ef60ca7ae] Merge branch 'di/readme-markup-fix'
git bisect bad 75ce48674889df6a2bb493fb5d6bef0ef60ca7ae
# good: [984da7f8d2589b53cca7c920e597eab30d4c1b36] Merge branch 'sr/gpg-interface-stop-at-the-end'
git bisect good 984da7f8d2589b53cca7c920e597eab30d4c1b36
# bad: [f8aee8576ac5e01fa993c80b5b888af214c03758] Merge branch 'tg/stash-keep-index-with-removed-paths'
git bisect bad f8aee8576ac5e01fa993c80b5b888af214c03758
# good: [b932f6a5e8cdbb33eff4563fdfb1eae9ebf70a65] stash: fix handling removed files with --keep-index
git bisect good b932f6a5e8cdbb33eff4563fdfb1eae9ebf70a65
# first bad commit: [f8aee8576ac5e01fa993c80b5b888af214c03758] Merge branch 'tg/stash-keep-index-with-removed-paths'

Which pinned point the failure starting from the moment the test was added at https://github.com/git/git/commit/b932f6a5e8cdbb33eff4563fdfb1eae9ebf70a65 by @t.gummerer

I would appreciate if we can either deprecate the GIT_TEST_STASH_USE_BUILTIN flag entirely or wrap the test with an 'if' so that we auto skip it when the flag is enabled.

Thanks,
Son Luong.

> On Feb 25, 2020, at 17:57, Junio C Hamano <gitster@pobox.com> wrote:
> 
> Son Luong Ngoc <son.luong@booking.com> writes:
> 
>> I have been trying to build git from source and noticing that some
>> tests have been failing since 2.25 with the flag
>> "GIT_TEST_STASH_USE_BUILTIN=false"
>> 
>> I think in 2.25 t3903.103 started to fail (rebase related) and
>> current master t3904 may be failing also.
>> 
>> Is "GIT_TEST_STASH_USE_BUILTIN=false" is still being tested with
>> or are we totally deprecating this flag?
> 
> In the longer term, when "git stash" gains new features that did not
> exist in the original scripted version, tests that observe how these
> features work would start failing when using the scripted version.
> 
> I picked some people from "git shortlog --no-merges builtin/stash.c"
> and placed them on the CC line---perhaps they may know more.  It
> happens that Johannes is also familiar with "rebase", which you
> said is involved in the test failure, so I'd imagine he would be the
> best person to ask.
> 
> Thanks for a report.
> 
> 