ci/run-build-and-tests: add some structure to the GitHub workflow output

The current output of Git's GitHub workflow can be quite confusing,
especially for contributors new to the project.

To make it more helpful, let's introduce some collapsible grouping.
Initially, readers will see the high-level view of what actually
happened (did the build fail, or the test suite?). To drill down, the
respective group can be expanded.

Note: sadly, workflow output currently cannot contain any nested groups
(see https://github.com/actions/runner/issues/802 for details),
therefore we take pains to ensure to end any previous group before
starting a new one.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ci/lib.sh

@@ -1,5 +1,50 @@
 # Library of functions shared by all CI scripts
 
+if test true != "$GITHUB_ACTIONS"
+then
+	begin_group () { :; }
+	end_group () { :; }
+
+	group () {
+		shift
+		"$@"
+	}
+	set -x
+else
+	begin_group () {
+		need_to_end_group=t
+		echo "::group::$1" >&2
+		set -x
+	}
+
+	end_group () {
+		test -n "$need_to_end_group" || return 0
+		set +x
+		need_to_end_group=
+		echo '::endgroup::' >&2
+	}
+	trap end_group EXIT
+
+	group () {
+		set +x
+		begin_group "$1"
+		shift
+		"$@"
+		res=$?
+		end_group
+		return $res
+	}
+
+	begin_group "CI setup"
+fi
+
+# Set 'exit on error' for all CI scripts to let the caller know that
+# something went wrong.
+#
+# We already enabled tracing executed commands earlier. This helps by showing
+# how # environment variables are set and and dependencies are installed.
+set -e
+
 skip_branch_tip_with_tag () {
 	# Sometimes, a branch is pushed at the same time the tag that points
 	# at the same commit as the tip of the branch is pushed, and building
@@ -88,12 +133,6 @@ export TERM=${TERM:-dumb}
 # Clear MAKEFLAGS that may come from the outside world.
 export MAKEFLAGS=
 
-# Set 'exit on error' for all CI scripts to let the caller know that
-# something went wrong.
-# Set tracing executed commands, primarily setting environment variables
-# and installing dependencies.
-set -ex
-
 if test -n "$SYSTEM_COLLECTIONURI" || test -n "$SYSTEM_TASKDEFINITIONSURI"
 then
 	CI_TYPE=azure-pipelines
@@ -138,7 +177,7 @@ then
 			test_name="${test_exit%.exit}"
 			test_name="${test_name##*/}"
 			printf "\\e[33m\\e[1m=== Failed test: ${test_name} ===\\e[m\\n"
-			cat "t/test-results/$test_name.out"
+			group "Failed test: $test_name" cat "t/test-results/$test_name.out"
 
 			trash_dir="t/trash directory.$test_name"
 			cp "t/test-results/$test_name.out" t/failed-test-artifacts/
@@ -233,3 +272,6 @@ linux-leaks)
 esac
 
 MAKEFLAGS="$MAKEFLAGS CC=${CC:-cc}"
+
+end_group
+set -x

ci/run-build-and-tests.sh

@@ -45,10 +45,10 @@ pedantic)
 	;;
 esac
 
-make
+group Build make
 if test -n "$run_tests"
 then
-	make test ||
+	group "Run tests" make test ||
 	handle_failed_tests
 fi
 check_unignored_build_artifacts

ci/run-test-slice.sh

@@ -10,7 +10,7 @@ windows*) cmd //c mklink //j t\\.prove "$(cygpath -aw "$cache_dir/.prove")";;
 *) ln -s "$cache_dir/.prove" t/.prove;;
 esac
 
-make --quiet -C t T="$(cd t &&
+group "Run tests" make --quiet -C t T="$(cd t &&
 	./helper/test-tool path-utils slice-tests "$1" "$2" t[0-9]*.sh |
 	tr '\n' ' ')" ||
 handle_failed_tests