sudo不起作用。我在用 BTRFS 格式化的 USB 密钥上安装了 Arch Linux。这是我运行“sudo”时的输出：
$ sudo
sudo: unable to stat /etc/sudoers: Permission denied
sudo: no valid sudoers sources found, quitting
sudo: unable to initialize policy plugin
$ ls -l /etc/sudoers
-r--r----- 1 root root 2849 May 18 15:00 /etc/sudoers
$ lsattr /etc/sudoers
--------------- /etc/sudoers
$ ls -ld /etc
drwxr-xr-x 1 root root 2476 May 25 13:45 /etc
$ ls -ld /
drwx------ 1 root root 142 May 25 06:51 /
$ ls -l $(which sudo)
---s--x--x …