then
                mkdir -p submodule_update/.git/modules/sub1/modules &&
                cp -r submodule_update_repo/.git/modules/sub1/modules/sub2 submodule_update/.git/modules/sub1/modules/sub2
-               # core.worktree is unset for sub2 as it is not checked out
+               GIT_WORK_TREE=. git -C submodule_update/.git/modules/sub1/modules/sub2 config --unset core.worktree
        fi &&
        # indicate we are interested in the submodule:
        git -C submodule_update config submodule.sub1.url "bogus" &&
                        git branch -t remove_sub1 origin/remove_sub1 &&
                        $command remove_sub1 &&
                        test_superproject_content origin/remove_sub1 &&
-                       ! test -e sub1 &&
-                       test_must_fail git config -f .git/modules/sub1/config core.worktree
+                       ! test -e sub1
                )
        '
        # ... absorbing a .git directory along the way.
                        : >sub1/untrackedfile &&
                        test_must_fail $command replace_sub1_with_file &&
                        test_superproject_content origin/add_sub1 &&
-                       test_submodule_content sub1 origin/add_sub1
+                       test_submodule_content sub1 origin/add_sub1 &&
                        test -f sub1/untracked_file
                )
        '
                        cd submodule_update &&
                        git branch -t add_sub1 origin/add_sub1 &&
                        : >sub1 &&
-                       echo sub1 >.git/info/exclude
+                       echo sub1 >.git/info/exclude &&
                        $command add_sub1 &&
                        test_superproject_content origin/add_sub1 &&
                        test_submodule_content sub1 origin/add_sub1
                        rm -rf .git/modules/sub1 &&
                        $command replace_sub1_with_directory &&
                        test_superproject_content origin/replace_sub1_with_directory &&
-                       test_submodule_content sub1 origin/modify_sub1
                        test_git_directory_exists sub1
                )
        '