Makefile: stop requiring Perl when running tests

The Makefile for our tests has a couple of targets that depend on Perl.
Adapt those targets to only run conditionally in case Perl is available
on the system so that it becomes possible to run the test suite without
Perl.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

t/Makefile

@@ -59,16 +59,21 @@ CHAINLINTSUPPRESS = GIT_TEST_EXT_CHAIN_LINT=0 && export GIT_TEST_EXT_CHAIN_LINT
 
 all:: $(DEFAULT_TEST_TARGET)
 
-test: pre-clean check-chainlint check-meson $(TEST_LINT)
+test: pre-clean check-meson $(TEST_LINT)
 	$(CHAINLINTSUPPRESS) $(MAKE) aggregate-results-and-cleanup
 
+ifneq ($(PERL_PATH),)
+test: check-chainlint
+prove: check-chainlint
+endif
+
 failed:
 	@failed=$$(cd '$(TEST_RESULTS_DIRECTORY_SQ)' && \
 		grep -l '^failed [1-9]' *.counts | \
 		sed -n 's/\.counts$$/.sh/p') && \
 	test -z "$$failed" || $(MAKE) $$failed
 
-prove: pre-clean check-chainlint $(TEST_LINT)
+prove: pre-clean $(TEST_LINT)
 	@echo "*** prove (shell & unit tests) ***"
 	@$(CHAINLINTSUPPRESS) TEST_OPTIONS='$(GIT_TEST_OPTS)' TEST_SHELL_PATH='$(TEST_SHELL_PATH_SQ)' $(PROVE) --exec ./run-test.sh $(GIT_PROVE_OPTS) $(T) $(UNIT_TESTS)
 	$(MAKE) clean-except-prove-cache
@@ -132,8 +137,13 @@ check-meson:
 		fi; \
 	done
 
-test-lint: test-lint-duplicates test-lint-executable test-lint-shell-syntax \
+test-lint: test-lint-duplicates test-lint-executable \
 	test-lint-filenames
+ifneq ($(PERL_PATH),)
+test-lint: test-lint-shell-syntax
+else
+GIT_TEST_CHAIN_LINT = 0
+endif
 ifneq ($(GIT_TEST_CHAIN_LINT),0)
 test-lint: test-chainlint
 endif