Comment 2 for bug 1874730

This is the error during upgrade:

Preparing to unpack .../840-phppgadmin_7.12.1+dfsg-1_all.deb ...
Unpacking phppgadmin (7.12.1+dfsg-1) over (5.1+ds-3) ...
...
Setting up phppgadmin (7.12.1+dfsg-1) ...
Installing new version of config file /etc/phppgadmin/config.inc.php ...
Package apache2 is not configured yet. Will defer actions by package phppgadmin.
...
info: Executing deferred 'a2enconf phppgadmin' for package phppgadmin
ERROR: Conf phppgadmin does not exist!
dpkg: error processing package apache2 (--configure):
 installed apache2 package post-installation script subprocess returned error exit status 1

The module wasn't able to be enabled after apache2 (and the module) was updated.