Problem with phpmyadmin in 18.04

[joneall]

I can neither uninstall nor configure phpmyadmin.

Installation of apache2 and php7.2 went smoothly. Installation of mysql has changed since16.04. Now you just install mysql-server and it installs the client automatically. But then you must run

sudo mysql_secure_installation

to configure it. This is new, at least to me.

Then when installing phpmyadmin, it asks which server, apache2 or something else, to use. That is where I messed up because I could not figure out how to choose apache2. (Need to use the space key. Who would have thought of that?) Frankly, I'm not sure what I did, but the subsequent installation of phpmyadmin failed. I tried purging it and doing all sorts of stuff I found on the web, like use 'rm -rf' to delete stuff by hand. Now I have this:

$ sudo apt install phpmyadmin php-mbstring php-gettext
Reading package lists... Done
Building dependency tree       
Reading state information... Done
php-gettext is already the newest version (1.0.12-0.1).
php-mbstring is already the newest version (1:7.2+60ubuntu1).
phpmyadmin is already the newest version (4:4.6.6-5).
Starting pkgProblemResolver with broken count: 0
Starting 2 pkgProblemResolver with broken count: 0
Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 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 phpmyadmin (4:4.6.6-5) ...
dbconfig-common: writing config to /etc/dbconfig-common/phpmyadmin.conf
dbconfig-common: flushing administrative password
dpkg: error processing package phpmyadmin (--configure):
installed phpmyadmin package post-installation script subprocess returned error exit status 10
Errors were encountered while processing:
phpmyadmin
E: Sub-process /usr/bin/dpkg returned an error code (1)

Suggestions on the internet say to fiddle around with stuff in /var/lib/dpkg/info/phpmyadmin.postinst, but that file is meaningless to me. Another suggestion gave this:

$ sudo dpkg --configure -a
Setting up phpmyadmin (4:4.6.6-5) ...
dbconfig-common: writing config to /etc/dbconfig-common/phpmyadmin.conf
dbconfig-common: flushing administrative password
dpkg: error processing package phpmyadmin (--configure):
installed phpmyadmin package post-installation script subprocess returned error exit status 10
Errors were encountered while processing:
phpmyadmin

How can I get past this hurdle? I would think that a complete removal of phpmyadmin would do the trick, but the arcana of package handling are beyond my ken.

[joneall]

Problem with apt package

I think my problem is with the package handler, something which is pretty much a black box to me. Following info found elsewhere on the web, I tried all of the following:

sudo rm  /var/lib/dpkg/info/phpmyadmin.*
sudo rm -rf /var/lib/phpmyadmin/
sudo apt-get autoclean
sudo dpkg --purge --force-remove-reinstreq  phpmyadmin

followed by a new install

$ sudo apt-get install  phpmyadmin
Reading package lists... Done
Building dependency tree       
Reading state information... Done
phpmyadmin is already the newest version (4:4.6.6-5).
Starting pkgProblemResolver with broken count: 0
Starting 2 pkgProblemResolver with broken count: 0
Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 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 phpmyadmin (4:4.6.6-5) ...
dbconfig-common: writing config to /etc/dbconfig-common/phpmyadmin.conf
Not replacing deleted config file /etc/phpmyadmin/config-db.php
dbconfig-common: flushing administrative password
dpkg: error processing package phpmyadmin (--configure):
installed phpmyadmin package post-installation script subprocess returned error exit status 10
Errors were encountered while processing:
phpmyadmin
E: Sub-process /usr/bin/dpkg returned an error code (1)

I even tried reinstalling dpkg ... and worse:

sudo apt-get install --reinstall dpkg

and

sudo rm /var/lib/dpkg/info/*.postint

since that the problem was with the post-installation script. All these operations followed suggestions at Ask Ubuntu or Stack Exchange.

Now the only postinst scripts in /var/lib/dpkg/info are for dkpg and phpmyadmin, I guess due to my having reinstalled them.

While phpmyadmin does seem to work, I am not happy seeing errors like this. What can that do to me in the future?