The following packages have been kept back:

因为有部份packages的安装版比release版新而出现”The following packages have been kept back”这个问题，解决方法是使用apt-get -u dist-upgrade 统一更新到发布的版本。这条命令会强制更新软件包到最新版本，并自动解决缺少的依赖包。