Re: [PATCH v2 3/3] travis: run tests with GIT_TEST_SPLIT_INDEX

[Lars Schneider <larsxschneider@gmail.com>]

> On 17 Dec 2017, at 23:51, Thomas Gummerer <t.gummerer@gmail.com> wrote:
> 
> Split index mode only has a few dedicated tests, but as the index is
> involved in nearly every git operation, this doesn't quite cover all the
> ways repositories with split index can break.  To use split index mode
> throughout the test suite a GIT_TEST_SPLIT_INDEX environment variable
> can be set, which makes git split the index at random and thus
> excercises the functionality much more thoroughly.
> 
> As this is not turned on by default, it is not executed nearly as often
> as the test suite is run, so occationally breakages slip through.  Try
> to counteract that by running the test suite with GIT_TEST_SPLIT_INDEX
> mode turned on on travis.
> 
> To avoid using too many cycles on travis only run split index mode in
> the linux-gcc and the linux 32-bit gcc targets.

I am surprised to see the split index mode test for the linux 32-bit
target. Is it likely that a split index bug appears only on 32-bit? 
Wouldn't the linux-gcc target be sufficient to save resources/time?


>  The Linux builds were
> chosen over the Mac OS builds because they tend to be much faster to
> complete.
> 
> The linux gcc build was chosen over the linux clang build because the
> linux clang build is the fastest build, so it can serve as an early
> indicator if something is broken and we want to avoid spending the extra
> cycles of running the test suite twice for that.
> 
> Helped-by: Lars Schneider <larsxschneider@gmail.com>
> Helped-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
> ---
> ci/run-linux32-build.sh | 1 +
> ci/run-tests.sh         | 4 ++++
> 2 files changed, 5 insertions(+)
> 
> diff --git a/ci/run-linux32-build.sh b/ci/run-linux32-build.sh
> index e30fb2cddc..f173c9cf2a 100755
> --- a/ci/run-linux32-build.sh
> +++ b/ci/run-linux32-build.sh
> @@ -27,4 +27,5 @@ linux32 --32bit i386 su -m -l $CI_USER -c '
>     cd /usr/src/git &&
>     make --jobs=2 &&
>     make --quiet test
> +    GIT_TEST_SPLIT_INDEX=YesPlease make --quiet test
> '
> diff --git a/ci/run-tests.sh b/ci/run-tests.sh
> index f0c743de94..c7aee5b9ff 100755
> --- a/ci/run-tests.sh
> +++ b/ci/run-tests.sh
> @@ -8,3 +8,7 @@
> mkdir -p $HOME/travis-cache
> ln -s $HOME/travis-cache/.prove t/.prove
> make --quiet test
> +if test "$jobname" = "linux-gcc"
> +then
> +	GIT_TEST_SPLIT_INDEX=YesPlease make --quiet test
> +fi

For now I think that looks good. Maybe we could define additional test 
configurations with an environment variable. That could be an array variable
defined in the lib-travis.ci "case" statement:
https://github.com/git/git/blob/1229713f78cd2883798e95f33c19c81b523413fd/ci/lib-travisci.sh#L42-L65


- Lars