function cacheDir(sourceDir, tool, version, arch) {
    return __awaiter(this, void 0, void 0, function* () {
        version = semver.clean(version) || version;
        arch = arch || os.arch();
        core.debug(`Caching tool ${tool} ${version} ${arch}`);
        core.debug(`source dir: ${sourceDir}`);
        if (!fs.statSync(sourceDir).isDirectory()) {
            throw new Error('sourceDir is not a directory');
        }
        // Create the tool dir
        const destPath = yield _createToolPath(tool, version, arch);
        // copy each child item. do not move. move can fail on Windows
        // due to anti-virus software having an open handle on a file.
        for (const itemName of fs.readdirSync(sourceDir)) {
            const s = path.join(sourceDir, itemName);
            yield io.cp(s, destPath, { recursive: true });
        }
        // write .complete
        _completeToolPath(tool, version, arch);
        return destPath;
    });
}
Caches a directory and installs it into the tool cacheDir

@param sourceDir    the directory to cache into tools
@param tool          tool name
@param version       version of the tool.  semver format
@param arch          architecture of the tool.  Optional.  Defaults to machine architecture