Merge branch 'ds/sparse-add'

Test fix.

* ds/sparse-add:
  t1091: don't grep for `strerror()` string

t/t1091-sparse-checkout-builtin.sh

@@ -305,7 +305,7 @@ test_expect_success 'fail when lock is taken' '
 	test_when_finished rm -rf repo/.git/info/sparse-checkout.lock &&
 	touch repo/.git/info/sparse-checkout.lock &&
 	test_must_fail git -C repo sparse-checkout set deep 2>err &&
-	test_i18ngrep "File exists" err
+	test_i18ngrep "Unable to create .*\.lock" err
 '
 
 test_expect_success '.gitignore should not warn about cone mode' '