sudo apt-get install php5-imagick 给出“404 Not Found”错误和“E: Failed to fetch ...”

Question

跑步：

sudo apt-get install php5-imagick 

失败，并产生输出，包括在中间：

Get:7 http://us.archive.ubuntu.com/ubuntu/ trusty/main libavahi-common3 amd64 0.6.31-4ubuntu1 [21.7 kB]
Get:8 http://us.archive.ubuntu.com/ubuntu/ trusty/main libavahi-client3 amd64 0.6.31-4ubuntu1 [25.1 kB]
Err http://us.archive.ubuntu.com/ubuntu/ trusty-updates/main libcups2 amd64 1.7.2-0ubuntu1.1
  404  Not Found [IP: 91.189.91.23 80]
Get:9 http://us.archive.ubuntu.com/ubuntu/ trusty-updates/main libcupsfilters1 amd64 1.0.52-0ubuntu1.2 [74.4 kB]
Get:10 http://us.archive.ubuntu.com/ubuntu/ trusty/main libfftw3-double3 amd64 3.3.3-7ubuntu3 [702 kB]
Err http://security.ubuntu.com/ubuntu/ trusty-security/main libcups2 amd64 1.7.2-0ubuntu1.1
  404  Not Found [IP: 91.189.92.200 80]
Err http://security.ubuntu.com/ubuntu/ trusty-security/main libcupsimage2 amd64 1.7.2-0ubuntu1.1
  404  Not Found [IP: 91.189.92.200 80]
Get:11 http://us.archive.ubuntu.com/ubuntu/ trusty/main libjasper1 amd64 1.900.1-14ubuntu3 [129 kB]
Get:12 http://us.archive.ubuntu.com/ubuntu/ trusty/main liblcms2-2 amd64 2.5-0ubuntu4 [132 kB]

最后是这个（指的是相同的错误）：

E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/c/cups/libcups2_1.7.2-0ubuntu1.1_amd64.deb  404  Not Found [IP: 91.189.92.200 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/c/cups/libcupsimage2_1.7.2-0ubuntu1.1_amd64.deb  404  Not Found [IP: 91.189.92.200 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

Answer 1

其他问题几乎是重复的，但有不同的错误信息和非常复杂的解决方案，所以发布这个问题和答案以尽量保持简单似乎是明智的。

就我而言，只需运行即可解决：

sudo apt-get update

希望其他人也会发现它也像这样简单:-)