新装ubuntukylin 16.04，sudo apt-get update 时遇到如下问题：
Hit:1 http://archive.ubuntukylin.com:10006/ubuntukylin xenial InRelease
Get:2 http://security.ubuntu.com/ubuntu xenial-security InRelease [102 kB]
Hit:3 http://us.archive.ubuntu.com/ubuntu xenial InRelease
Get:4 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB]
Ign:5 http://apt.newrelic.com/debian newrelic InRelease
Hit:6 http://apt.newrelic.com/debian newrelic Release
Get:7 http://apt.newrelic.com/debian newrelic Release.gpg [181 B]
Get:8 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]
Fetched 307 kB in 7s (39.4 kB/s)
Reading package lists... Done
W: http://archive.ubuntukylin.com:10006/ubuntukylin/dists/xenial/InRelease: Signature by key 6CE35A4EBAB676094476BE7CD259B7555E1D3C58 uses weak digest algorithm (SHA1)
解决办法：
system setting-->>Softerware update -->> Other softerware
把ubuntukylin的源全部去掉（把勾点掉）就行了
之后再更新就ok了
参考链接
W: http://archive.ubuntukylin.com:10006/ubuntukylin/dists/xenial/InRelease: Signature by key 6CE35A4EBAB676094476BE7CD259B7555E1D3C58 uses weak digest algorithm (SHA1)
原文：http://www.cnblogs.com/longsecond/p/6282335.html
