On Fri, Jan 15 2021, Ævar Arnfjörð Bjarmason wrote:

 test_expect_success 'cherry picks did not become git merge commits' '
 	bad_cherries=$(git rev-list --parents --all --grep=Cherry |
-		grep " .* " | cut -f1 -d" ") &&
+		test_might_fail ok=sigpipe grep grep " .* " | cut -f1 -d" ") &&
[...]
-		grep " .* " | cut -f1 -d" ") &&
+		test_might_fail ok=sigpipe grep grep " .* " | cut -f1 -d" ") &&

So, "grep grep" is an obvious typo there. Oops. The test still passes
because it's fragile to begin with, we're just checking that we get no
output, so "grep this string is not here" would also pass.