我在 Ubuntu 18.04 与 MySQL 5.7.24 我正在尝试启用 general_log 如本文所述。
所以在我的 /etc/mysql/my.cnf 我补充说：

general_log = on
general_log_file=/tmp/mysql.log

然后我停止并再次启动mysql，但我得到一个错误：

$ sudo service mysql stop
$ sudo service mysql start
Job for mysql.service failed because the control process exited with error code.
See "systemctl status mysql.service" and "journalctl -xe" for details.

所以我退房了 systemctl status mysql.service ```
● mysql.service - MySQL Community Server
Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Fri 2019-01-04 17:50:31 CET; 45s ago
Process: 27206 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/run/mysqld/mysqld.pid (code=exited, status=0/SUCCESS)
Process: 27613 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=1/FAILURE)
Main PID: 27208 (code=exited, status=0/SUCCESS)

Jan 04 17:50:31 librem systemd[1]: mysql.service: Failed with result 'exit-code'.
Jan 04 17:50:31 librem systemd[1]: Failed to start MySQL Community Server.
Jan 04 17:50:31 librem systemd[1]: mysql.service: Service hold-off time over, scheduling restart.
Jan 04 17:50:31 librem systemd[1]: mysql.service: Scheduled restart job, restart counter is at 5.
Jan 04 17:50:31 librem systemd[1]: Stopped MySQL Community Server.
Jan 04 17:50:31 librem systemd[1]: mysql.service: Start request repeated too quickly.
Jan 04 17:50:31 librem systemd[1]: mysql.service: Failed with result 'exit-code'.
Jan 04 17:50:31 librem systemd[1]: Failed to start MySQL Community Server.

在 `journalctl -xe` 我也差不多。
我尝试在中创建日志文件 `/tmp/mysql.log` 把它交给 `777` ，但在这样做之后，启动mysql失败，并出现相同的错误。
有人知道这里怎么了吗？