我一直在尝试在 Ubuntu 16.04 上卸载并重新安装 MySQL，我见过很多方法，但我不知道为什么会出现错误。
$ sudo apt-get install mysql-server
mysql-server is already the newest version (5.7.17-0ubuntu0.16.04.2).
The following package was automatically installed and is no longer required:
snap-confine
Use 'sudo apt autoremove' to remove it.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
2 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n]
Setting up mysql-server-5.7 (5.7.17-0ubuntu0.16.04.2) ...
Renaming removed key_buffer …