ubuntu 命令行sudo apt-get update
W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn‘t be verified because the public key is not available: NO_PUBKEY 2EE5793634EF4A35
出现W: GPG 错误：http://ppa.launchpad.net lucid Release: 由于没有公钥，无法验证下列签名： NO_PUBKEY FAF69C646FF368B7的问题，可以在终端中运行：
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 2EE5793634EF4A35
error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because
原文：http://www.cnblogs.com/chaihy/p/7573119.html