問題描述：
多次在apt install時候遇到E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing? 的error。
Error報的信息顯示是這個包向source里的資源下載失敗了，但是原因是多種多樣的，這里做了個總結，以防下次踩坑：
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問題解決：
1- source本身的問題
根據提示，我們首先應當 apt-get update 一下source,如果在apt-get update后依然報這個error，那就說明這個source本省就有錯誤，嘗試apt-get update --fix-missing后依舊報這個error，果斷換source。
輸入命令：
sudo cp sources.list sources.list.bak
就是先將sources.list備份到sources.list.bak
將 /etc/apt/sources.list 的內容換成：
# deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main restricted
deb-src http://archive.ubuntu.com/ubuntu xenial main restricted #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial main restricted multiverse universe #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted multiverse universe #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb http://mirrors.aliyun.com/ubuntu/ xenial multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse #Added by software-properties
deb http://archive.canonical.com/ubuntu xenial partner
deb-src http://archive.canonical.com/ubuntu xenial partner
deb http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted multiverse universe #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial-security universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-security multiverse
更多源請參考：https://www.cnblogs.com/X-knight/p/10598498.html
最后sudo apt-get update一下就OK了。
2- 網絡的問題
網關錯誤攔截了數據包或者防火牆故意將其屏蔽在外（比方update 包含有google-chrome瀏覽器的source時候，ip 會自動重定向至6.6.6.6）
sudo vim /etc/resolv.conf
添加：
nameserver 8.8.8.8
nameserver 223.5.5.5
nameserver 223.6.6.6
或是換網絡試一下或者參見該配置代理即可。
最后sudo apt-get update一下就OK了。