GPG error: The following signatures couldn't be verified because the public key

    在apt-get update时出现这样的类似错误：

写道

W: GPG error: http://ppa.launchpad.net karmic Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY D45DF2E8FC91AE7E

 

    解决办法：

写道

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys  D45DF2E8FC91AE7E

 

    然后在apt-get update一下就可以了。