设置狗日的代理。。。
sudo apt-get -o Acquire::http::proxy="http://127.0.0.1:8000/" update
Acquire::http::proxy "http://127.0.0.1:8000/";
Acquire::ftp::proxy "ftp://127.0.0.1:8000/";
Acquire::https::proxy "https://127.0.0.1:8000/";
from http://dargoner.javaeye.com/blog/731721