t/Makefile: add a rule to re-run previously-failed tests

diff --git a/t/lib-submodule-update.sh b/t/lib-submodule-update.sh
index 79cdd34a540ddc7230b1aefb7fb4af5915c7085f..915eb4a7c65ca5c574beddc676bf0115990eec3f 100755 (executable)
--- a/t/lib-submodule-update.sh
+++ b/t/lib-submodule-update.sh
@@ -69,10 +69,7 @@ create_lib_submodule_repo () {
 
                git checkout -b "replace_sub1_with_directory" "add_sub1" &&
                git submodule update &&
-               (
-                       cd sub1 &&
-                       git checkout modifications
-               ) &&
+               git -C sub1 checkout modifications &&
                git rm --cached sub1 &&
                rm sub1/.git* &&
                git config -f .gitmodules --remove-section "submodule.sub1" &&