Comment 2 for bug 1795332

Thanks for filing this bug in Ubuntu.

This is the error:
Installing new version of config file /etc/mysql/debian-start ...
Renaming removed key_buffer and myisam-recover options (if present)
ERROR: Unable to start MySQL server:
2018-10-01T07:00:11.667268Z 0 [ERROR] unknown variable 'myisam_recover=BACKUP'
2018-10-01T07:00:11.674546Z 0 [ERROR] Aborting
Please take a look at https://wiki.debian.org/Teams/MySQL/FAQ for tips on fixing common upgrade issues.
Once the problem is resolved, run apt-get --fix-broken install to retry.
dpkg: error processing package mysql-server-5.7 (--configure):
 subprocess installed post-installation script returned error exit status 1

The myisam-recover option was renamed a long time ago. From the mysql 5.5 documentation:
"""
This option was renamed in MySQL 5.5.3 to --myisam-recover-options. See the description of that option for more information.
"""

Looks like the postinst script attempted to rename it:
"""
Renaming removed key_buffer and myisam-recover options (if present)
"""

Your attached /etc/mysql/mysql.conf.d/mysqld.cnf file shows it renamed:
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
myisam-recover-options = BACKUP

But you still have it in /etc/mysql/my.cnf:
myisam_recover = BACKUP

I see that this file has a header that indicates it was generated by another tool:
# DO NOT CHANGE THIS FILE!
# This config is generated by SALTSTACK
# and all change will be overrided on next salt call

So I believe you need to update your "SALTSTACK" templates/scripts, and this is not an error in the mysql packaging. I'll therefore mark this bug as invalid.

If my analysis is incorrect, please reopen the bug stating your reasoning.

Thanks!