Bsrgvty

Today I got the same problem, after trying many solutions i found that the problem was the command sudo systemctl disable mysql.service that i used to disable MySQL auto starting, so to get it working i re-enabled again MySQL server using the command sudo systemctl enable mysql.service and run again the upgrade process and it terminated perfectly.

Your error message contains this line:

subprocess installed post-installation script returned error exit status 1

However, this installed post-installation script is not mentioned by name. After much tinkering, I found out that its name is (in my case) /var/lib/dpkg/info/mysql-server-5.7.postinst.

Open this file with sudo vi /var/lib/dpkg/info/mysql-server-5.7.postinst, or your preferred editor.

At the top, change line 3 (or so): set -e to set -x, save the file. (option -e is "exit on errors", -x means "explicitly show command executed", presumably)

Run sudo dpkg --configure -a --log /tmp/dpkg.log
(the --log option is optional). You can also simply run apt upgrade if you know it'll be the only package that will be upgraded.

Now you get verbose output of the mysql-server-5.7.postinst bash script, and you can figure out what's wrong.

In my case it unsuccessfully tried to (re-)run mysql_upgrade, but that was not needed for my customized mysql installation. I was sure I've run it manually before, successfully, and all was well.

So I commmented out line 321 (for older mysqld releases try line 281),

#mysql_upgrade --defaults-file=/etc/mysql/debian.cnf || result=$?

and the command that has failed before, sudo apt upgrade (run it again), finished successfully, and dpkg removed the error status for this package.

Now you can set back the set -x to set -e (mentioned above). And optionally uncomment the mysql-upgrade line.

Extra work might be required if you have moved your mysql data partition to a nonstandard location. I moved mine from /var/lib/mysql/data to a different drive via symlink. Then you might have to remove the symbolic link temporarily, before the postinst script manipulation. Then re-create it after running the package upgrade.

After the next minor version upgrade of the mysqld debian package, this problem with the /var/lib/dpkg/info/mysql-server-5.7.postinst script can show up again.

The instructions here fixed it on my server: https://bugs.mysql.com/bug.php?id=72722

I can understand the pain of having your system in inconsistent state
but lets not worry about the whole situation and take it step by step
to get the system clean.

First lets see the current state of all the mysql packages on machine
using: dpkg -l | grep mysql (Please paste the output excluding last
column)

The first column denotes the current status of the package. Here are
the possible options:

ii) Installed rc) Removed config-files kept (This should be the state
of all the packages you have removed with 'apt-get remove' that does
not remove config-files under /etc)

For this to work, you will need to run 'apt-get purge ' till
you do not see any packages in the above list.

Please remember that some non-mysql-server packages like
python-mysql.connector and python-mysqldb, if installed, need not be
removed as they do not have any affect on this situation but if
removed might cause trouble to applications using them.

We will definitely try to re-visit our docs to see how can we
safeguard users from getting into this trouble. Thanks for sharing
your feedback in detail with us.

In my case, with strace, I saw that /var/run/mysqld/ didn't exist and mysqld can't create the file mysqld.sock.

These commands solved my problem:

mkdir /var/run/mysqld
chown mysql.mysql /var/run/mysqld
chmod 700 /var/run/mysqld

Now:

systemctl start mysql

And mysql works again :)

In my case I could solv the problem by adding

# Allow log file access
/home/system/var/log/mysql.err rw,
/home/system/var/log/mysql.log rw,
/home/system/var/log/mysql/ r,
/home/system/var/log/mysql/** rw,

to /etc/apparmor.d/local/usr.sbin.mysqld

For more details take a look at my answer (by ChristophS) at stackoverflow.

None of the answers on this page worked for me.

I ended up going to the Oracle downloads page, downloading mysql-apt-config_0.8.8-1_all.deb, and installing MySQL from Oracle repo:

sudo dpkg -i mysql-apt-config_0.8.8-1_all.deb
sudo apt update
sudo apt install mysql-server

I had the same issue. I tried to re-install mysql several times, but had no success.

I figured out that the problem for me was, that another mysql process was already running.

In details:

After I read carefully logs in /var/log/mysql/error.log, and found:

[ERROR] Can't start server: Bind on TCP/IP port: Address already in
use

[ERROR] Do you already have another mysqld server running on port:
3306 ?

Looks like another application was using already the port.

I checked it using ps -aux | grep 3306:

$ ps -aux | grep 3306
milkovs+ 6802 0.0 0.0 16336 1084 pts/19 S+ 21:39 0:00 grep --color=auto 3306
mysql 14706 0.0 0.3 1270192 13916 pts/2 Sl Aug19 0:29 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --user=mysql --skip-grant-tables --log-error=/var/log/mysql/error.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock --port=3306 --log-syslog=1 --log-syslog-facility=daemon --log-syslog-tag=

And I killed the running process sudo kill -15 14706

Then I started mysql: /etc/init.d/mysql start

Finally mysql works for me! I hope it helps somebody.

I have had the issue on a few servers now
The fix was to run
apt install phpmyadmin --reinstall

which resolved the above (with no need to touch mysql afterwards)