protected function fetchRepositoryUpdates(PackageInterface $package, $path, $url)
    {
        /**
         * Copy-pasted from doUpdate
         *
         * @see GitDownloader::doUpdate()
         */
        $this->io->write('    Checking out ' . $package->getSourceReference());
        $command = $this->getFetchCommand();
        $commandCallable = function ($url) use ($command) {
            return sprintf($command, ProcessExecutor::escape($url));
        };
        $this->gitUtil->runCommand($commandCallable, $url, $path);
        return $this;
    }