W: GPG error: http://archive.ubuntukylin.com trusty Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY D259B7555E1D3C58

貌似是公钥不可以用了，需要获取新的key，命令如下：


10:02linc@Linc-Ubuntu:~$ sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys D259B7555E1D3C58 
Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /tmp/tmp.JXx8td77hP --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver keyserver.ubuntu.com --recv-keys D259B7555E1D3C58 
gpg: requesting key 5E1D3C58 from hkp server keyserver.ubuntu.com 
gpg: key 5E1D3C58: public key "Ubuntu Kylin Archive Automatic Signing Key <[email protected]>" imported 
gpg: Total number processed: 1 
gpg:               imported: 1  (RSA: 1)