tests: add verbose output when unmounting

tests/example_filesystems/example_filesystems_test.go

@@ -24,7 +24,7 @@ func TestMain(m *testing.M) {
 	flag.Parse()
 	for _, opensslOpt = range []string{"-openssl=false", "-openssl=true"} {
 		if testing.Verbose() {
-			fmt.Printf("TestMain: testing with %q\n", opensslOpt)
+			fmt.Printf("example_filesystems: testing with %q\n", opensslOpt)
 		}
 		test_helpers.ResetTmpDir(true)
 		r := m.Run()

tests/test_helpers/helpers.go

@@ -49,6 +49,9 @@ func ResetTmpDir(plaintextNames bool) {
 			d := filepath.Join(TmpDir, e.Name())
 			err = os.Remove(d)
 			if err != nil {
+				if testing.Verbose() {
+					fmt.Printf("%v, trying umount\n", d, err)
+				}
 				UnmountErr(d)
 				err = os.RemoveAll(d)
 				if err != nil {