composer 无法更新 packagist.org 有缓存？跟 github.com 不一样

composer clear-cache
rm -rf vendor/*
composer update -vvv

  - Installing g9901/yii2-gftp (2.0.1)
Downloading https://api.github.com/repos/G9901/yii2-gftp/zipball/5621e075a25d13b83587f6293ff35c0ee00f1769
    Downloading: 100%
Writing /root/.composer/cache/files/g9901/yii2-gftp/5621e075a25d13b83587f6293ff35c0ee00f1769.zip into cache
    Extracting archive
Executing command (CWD): unzip '/home/flxx/basic/vendor/g9901/yii2-gftp/74b544ff38bad8cd15f4e57f4fea1bd4' -d '/home/flxx/basic/vendor/composer
/befb67d9' && chmod -R u+w '/home/flxx/basic/vendor/composer/befb67d9'

    REASON: Required by root: Install command rule (install g9901/yii2-gftp 2.0|install g9901/yii2-gftp 2.0.1)

很奇怪的现象，下载到目录的 g9901/yii2-gftp 还是旧的，跟 github.com 上的源码不一样！

下载来的源码：

phppublic function login () {
        $this->connectIfNeeded(false);
        $this->handle->login();
        $this->onLogin(new Event(['sender' => $this, 'data' => $user]));
}

github.com 上的源码：

phppublic function login () {
        $this->connectIfNeeded(false);
        $this->handle->login();
        $this->onLogin(new Event(['sender' => $this, 'data' => $this->handle->user]));
}

已经在 packagist.org 上点击了 “update” 按钮很多次了。 https://packagist.org/packages/g9901/yii2-gftp，奇怪的是packagist 显示的最后修改时间还是 2015-07-15 20:04 UTC