递归复制目录

Question

我有一个递归复制目录的函数。但是我收到了错误：

Fatal error: Uncaught exception 'UnexpectedValueException' with message 'RecursiveDirectoryIterator::__construct(/temp/install_5630013a79723/site, /temp/install_5630013a79723/site): The system cannot find the file specified. (code: 2)'

public static function copyDir($source, $dest) {

            @mkdir($dest, 0755);
            foreach ($iterator = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($source, \RecursiveDirectoryIterator::SKIP_DOTS),  \RecursiveIteratorIterator::SELF_FIRST) as $item) {
              if ($item->isDir()) {
                @mkdir($dest . DIRECTORY_SEPARATOR . $iterator->getSubPathName());
              } else {
                @copy($item, $dest . DIRECTORY_SEPARATOR . $iterator->getSubPathName());
              }
            }
        }

如何修复/改善我的功能？