Re: [PATCH 8/8] t/test-lib: make feature-testbed job more accessible

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Patrick

On 27/10/2026 08:18, Patrick Steinhardt wrote:
> Our "feature-testbed" job sets up a bunch of GIT_TEST environment
> variables and then executes our tests. This is mostly intended as a
> testbed for features that aren't default-enabled, but that may
> eventually become so.
> 
> Due to the job being special it has a higher potential of failing even
> though a local test run succeeds. But running these tests locally with
> the same environment is somewhat painful, as the developer has to
> manually set all of these environment variables.
> 
> Introduce a new "--feature-testbed" toggle for our test suite that, when
> set, sets up exactly these environment variables. Migrate our CI to use
> this toggle so that we have a single source of truth, only.
> 
> Note that we only set these GIT_TEST variables in the case where they
> haven't already been configured. This serves two purposes:
> 
>    - The user can continue to manually override a subset of those
>      variables, if they desire.
> 
>    - Test scripts typically source "t/test-lib.sh" after they already
>      overrode GIT_TEST variables, and we don't want to discard that.

That all sounds sensible, the commit message could maybe flag that the 
"feature-testbed" also sets OPENSSL_SHA1_UNSAFE which 
"--feature-testbed" does not because it is only concerned with GIT_TEST_*.

> diff --git a/t/test-lib.sh b/t/test-lib.sh
> index de566309861..8863bcac930 100644
> --- a/t/test-lib.sh
> +++ b/t/test-lib.sh
> @@ -202,6 +202,14 @@ finalize_test_case_output () { :; }
>   finalize_test_leak_output () { :; }
>   finalize_test_output () { :; }
>   
> +set_default_env () {
> +	if eval "test -z \"\${$1+set}\""

This made me scratch my head for a couple of minutes, but I think it is 
correct

	set_default_env ABC 1

evaluates

	test -z "${ABC+set}"

to see if $ABC is unset.

Thanks

Phillip
> +	then
> +		eval "$1=\$2"
> +	fi
> +	export "$1"
> +}
> +
>   parse_option () {
>   	local opt="$1"
>   
> @@ -212,6 +220,19 @@ parse_option () {
>   		immediate=t ;;
>   	-l|--l|--lo|--lon|--long|--long-|--long-t|--long-te|--long-tes|--long-test|--long-tests)
>   		GIT_TEST_LONG=true; export GIT_TEST_LONG ;;
> +	--feature-testbed)
> +		set_default_env GIT_TEST_SPLIT_INDEX yes
> +		set_default_env GIT_TEST_FULL_IN_PACK_ARRAY true
> +		set_default_env GIT_TEST_OE_SIZE 10
> +		set_default_env GIT_TEST_OE_DELTA_SIZE 5
> +		set_default_env GIT_TEST_COMMIT_GRAPH 1
> +		set_default_env GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS 1
> +		set_default_env GIT_TEST_MULTI_PACK_INDEX 1
> +		set_default_env GIT_TEST_MULTI_PACK_INDEX_WRITE_INCREMENTAL 1
> +		set_default_env GIT_TEST_NO_WRITE_REV_INDEX 1
> +		set_default_env GIT_TEST_CHECKOUT_WORKERS 2
> +		set_default_env GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL 1
> +		;;
>   	-r)
>   		mark_option_requires_arg "$opt" run_list
>   		;;
> diff --git a/t/unit-tests/unit-test.c b/t/unit-tests/unit-test.c
> index 752fb38fb32..f4898353045 100644
> --- a/t/unit-tests/unit-test.c
> +++ b/t/unit-tests/unit-test.c
> @@ -27,6 +27,7 @@ int cmd_main(int argc, const char **argv)
>   		 * options understood by integration tests.
>   		 */
>   		OPT_NOOP_NOARG('d', "debug"),
> +		OPT_NOOP_NOARG(0, "feature-testbed"),
>   		OPT_NOOP_NOARG(0, "github-workflow-markup"),
>   		OPT_NOOP_NOARG(0, "no-bin-wrappers"),
>   		OPT_NOOP_ARG(0, "no-chain-lint"),
>