[PATCH 3/4] Makefile: add a NO_TEST_TOOLS flag

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Add a NO_TEST_TOOLS flag to build an installable git, but one that
can't run "make test". This is useful e.g. in CI environments where
you'd like to run external tests against a built git, but have no
desire to run git's own tests.

On my 8 core machine this saves me around 1 second out of an otherwise
11-12 second build time. So it doesn't make all the difference, but
when you're wanting to run tests against a lot of git versions it adds
up.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 Makefile      | 6 ++++++
 t/test-lib.sh | 5 +++++
 2 files changed, 11 insertions(+)

diff --git a/Makefile b/Makefile
index 4031fb1b22f..cfa7bc58edf 100644
--- a/Makefile
+++ b/Makefile
@@ -309,6 +309,9 @@ all::
 #
 # Define NO_TCLTK if you do not want Tcl/Tk GUI.
 #
+# Define NO_TEST_TOOLS if you'd like to skip building the assets
+# required to run the tests. 
+#
 # Define SANE_TEXT_GREP to "-a" if you use recent versions of GNU grep
 # and egrep that are pickier when their input contains non-ASCII data.
 #
@@ -2732,6 +2735,7 @@ GIT-BUILD-OPTIONS: FORCE
 	@echo NO_PERL=\''$(subst ','\'',$(subst ','\'',$(NO_PERL)))'\' >>$@+
 	@echo NO_PTHREADS=\''$(subst ','\'',$(subst ','\'',$(NO_PTHREADS)))'\' >>$@+
 	@echo NO_PYTHON=\''$(subst ','\'',$(subst ','\'',$(NO_PYTHON)))'\' >>$@+
+	@echo NO_TEST_TOOLS=\''$(subst ','\'',$(subst ','\'',$(NO_TEST_TOOLS)))'\' >>$@+
 	@echo NO_UNIX_SOCKETS=\''$(subst ','\'',$(subst ','\'',$(NO_UNIX_SOCKETS)))'\' >>$@+
 	@echo PAGER_ENV=\''$(subst ','\'',$(subst ','\'',$(PAGER_ENV)))'\' >>$@+
 	@echo DC_SHA1=\''$(subst ','\'',$(subst ','\'',$(DC_SHA1)))'\' >>$@+
@@ -2787,8 +2791,10 @@ GIT-PYTHON-VARS: FORCE
             fi
 endif
 
+ifndef NO_TEST_TOOLS
 test_bindir_programs := $(patsubst %,bin-wrappers/%,$(BINDIR_PROGRAMS_NEED_X) $(BINDIR_PROGRAMS_NO_X) $(TEST_PROGRAMS_NEED_X))
 TEST_TOOLS = $(TEST_PROGRAMS) $(test_bindir_programs)
+endif
 
 all:: $(TEST_TOOLS)
 
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 03c1c0836f1..4029cd18031 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -55,6 +55,11 @@ then
 	exit 1
 fi
 . "$GIT_BUILD_DIR"/GIT-BUILD-OPTIONS
+if test -n "$NO_TEST_TOOLS"
+then
+	echo >&2 'error: NO_TEST_TOOLS=$NO_TEST_TOOLS set in GIT-BUILD-OPTIONS, cannot run tests!.'
+	exit 1
+fi
 export PERL_PATH SHELL_PATH
 
 # Disallow the use of abbreviated options in the test suite by default
-- 
2.29.2.222.g5d2a92d10f8