List<String> listedVersions;
        if (revisionMatchesDirectoryName(pattern)) {
            ExternalResourceName parent = versionListPattern.getRoot().resolve(prefix);
            listedVersions = listAll(parent, result);
        } else {
            int parentFolderSlashIndex = prefix.lastIndexOf(fileSeparator);

	}

	var cmd string
	switch *testSum {
	case "tidy":
		cmd = "go mod tidy"
	case "listm":
		cmd = "go list -m -mod=mod all"
	case "listall":
		cmd = "go list -mod=mod all"
	default:
		t.Fatalf(`unknown value for -testsum %q; may be "tidy", "listm", or "listall"`, *testSum)
	}

	log := new(strings.Builder)
	err := e.Execute(s, "updateSum", bufio.NewReader(strings.NewReader(cmd)), log)
	if log.Len() > 0 {