Subject: bug#586: exim 4.94.2 update default configuration option breaks MTA

From: [email-masked]
Date: Fri, 25 Jun 2021 12:45:28 -0300

Package: exim4
Version: 4.94
Severity: high

Half way through the update to exim 4.94.2, the installer pops up a 
warning in the terminal informing that the configuration file being 
installed was different to the one in place and prompts to choose 
what to do:

1. keep the installed configuration (default)
2. install the new configuration
3. check and compare the differences in order to choose.

In most default Devuan Beowulf installations the installer will be 
referring to the [c]/etc/exim4/exim4.conf.template[/c] which is used 
by the default non-split configuration scheme used by most anyone 
running a Devuan Beowulf desktop box.

Most users will choose the (recommended) default option.

In doing so they will unknowingly break their exim4 installation.

The result is a non-working MTA, with system mail being held.

ie: not delivered to /var/mail/user folder while at the same time 
/var/log/exim4/paniclog slowly grows in size.

With all versions of exim previous to version 4.94.2 now rendered 
obsolete, exim 4.94.2 will break any and all configurations set up 
with previous versions of the package.

This happens whether it uses the default configuration ie: the 
non-split configuration scheme which uses the 
/etc/exim4/exim4.conf.template file or the split configuration scheme 
used in more complex installations and which you can eventually opt 
for when installing Devuan or by running dpkg-reconfigure 
exim4-config later on.

exim 4.94.2 is absolutely incompatible with any configuration files 
used/generated with versions previous to version 4.94.2.

Which, at least for *this* very significant update, makes the 
(default) option to keep an existing configuration a serious problem.

Doing so will keep back the exim-config 4.94.2 package and make a 
mess.

Please don't ask how I know this.

Thanks in advance,

Carlos Izzo Videla