pkexec visudo
==== AUTHENTICATING FOR org.freedesktop.policykit.exec ===
Authentication is needed to run `/usr/sbin/visudo' as the super user
Authenticating as: Thomas,,, (tuc) Password: polkit-agent-helper-1:
error response to PolicyKit daemon:
GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: No session for
cookie
==== AUTHENTICATION FAILED ===
Error executing command as another user: Not authorized
This incident has been reported.
我是通过 ssh 执行此操作的，因为我正在执行此操作的盒子用作没有屏幕的音乐服务器，并且无法访问。这发生在我从 Ubuntu 14.04 升级到 16.04 时。我试图从另一个最近的 16.04 安装中复制一个 sudoers 文件，但由于 sudoers 文件，我无法这样做：
sudo mv ~/gyrf sudoers
>> /etc/sudoers: syntax error near line 36 …