sudo apt-get update 错误 解决方法

说明：

$ sudo apt-get update

错误如下：

W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://extras.ubuntu.com precise Release: The following signatures were invalid: BADSIG 16126D3A3E5C1192 Ubuntu Extras Archive Automatic Signing Key <ftpmaster@ubuntu.com>

W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/precise/Release

W: Some index files failed to download. They have been ignored, or old ones used instead.

 

解决方法：

$ sudo rm -rf /var/lib/apt/lists/*

$ sudo apt-get update