In the early days of Git, Perl was used quite prominently throughout the project. This has changed significantly as almost all of the executables we ship nowadays have eventually been rewritten in C. Only a handful of subsystems remain that require Perl: - gitweb, a read-only web interface. - A couple of scripts that allow importing repositories from GNU Arch, CVS and Subversion. - git-send-email(1), which can be used to send mails. - git-request-pull(1), which is used to request somebody to pull from a URL by sending an email. - git-filter-branch(1), which uses Perl with the `--state-branch` option. This command is typically recommended against nowadays in favor of git-filter-repo(1). - Our Perl bindings for Git. - The netrc Git credential helper. None of these subsystems can really be considered to be part of the "core" of Git, and an installation without them is fully functional. It is more likely than not that an end user wouldn't even notice that any features are missing if those tools weren't installed. But while Perl nowadays very much is an optional dependency of Git, there is a significant limitation when Perl isn't available: developers cannot run our test suite. Preceding commits have started to lift this restriction by removing the strict dependency on Perl in many central parts of the test library. But there are still many tests that rely on small Perl helpers to do various different things. Introduce a new PERL_TEST_HELPERS prerequisite that guards all tests that require Perl. This prerequisite is explicitly different than the preexisting PERL prerequisite: - PERL records whether or not features depending on the Perl interpreter are built. - PERL_TEST_HELPERS records whether or not a Perl interpreter is available for our tests. By having these two separate prerequisites we can thus distinguish between tests that inherently depend on Perl because the underlying feature does, and those tests that depend on Perl because the test itself is using Perl. Adapt all tests to set the PERL_TEST_HELPERS prerequisite as needed. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>