bash on windows 升级 16.04

首先替换14.04源（阿里云）

deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse

按照官方推荐方式，进行升级

sudo aptitude install update-manager-core
sudo do-release-upgrade

# 提示如下信息，升级失败
[screen is terminating]

后Google找到解决办法

sudo -S RELEASE_UPGRADER_NO_SCREEN=1 do-release-upgrade

升级后，sudo不能直接使用，必须带上-S。通过如下方法解决：

echo "alias sudo='sudo -S'" >> ~/.bash_aliases