：confuse: signature from "Thorsten Töpper atsutane@freethoughts.de" is unknown trust
解决:
$ sudo pacman-key --refresh-keys
arch错误：无法准备事务处理 (无法满足依赖关系) :: package-query: 要求 pacman<4.3
解决:
$ sudo pacman -R package-query yaourt
更新python2-pip出现问题
$ sudo pacman -Syu
错误：无法提交处理 (有冲突的文件)
python2-pip: 文件系统中已存在 /usr/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/contrib/socks.py
python2-pip: 文件系统中已存在 /usr/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/contrib/socks.pyc
发生错误，没有软件包被更新。
解决:
$ sudo mv /usr/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/contrib/socks.py ~/
$ sudo mv /usr/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/contrib/socks.py~ ~/
$ sudo pacman -Syu # 我也不清楚为什么会发生这个问题，只能这样解决了
$ sudo cp ~/sock.py /usr/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/contrib/
$ sudo cp ~/sock.py~ /usr/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/contrib/
