package dovecot-core 1:2.3.16+dfsg1-3ubuntu2.1 failed to install/upgrade with managesieve_notify_capability configuration setting

Hello,
Thank you for the bug report. I was unable to reproduce your error when upgrading from 20.04 to 22.04 with a dovecot.conf file containing managesieve_notify_capability. However, the error does show up on both 20.04 and 22.04 if dovecot-managesieved is not installed.

Do you know if it is installed on your system? If not you can try installing and restarting dovecot to see if that works with the following commands:

sudo apt install dovecot-managesieved
sudo systemctl restart dovecot
sudo systemctl status dovecot

If this still doesn't work would you be willing to share your /etc/dovecot/dovecot.conf file to this bug? Just make sure to remove any sensitive information first.

Thanks!

I believe that I did not have dovecot-managesieved installed. I assume that it was installed at some point.

Since the error occurred on a production system during the process of updating to 22.04, I can't readily use the system to try installing/uninstalling it.

Thanks Bill. You mentioned 'managesieve_notify_capability' is not supported in current dovecot - if you saw this documented somewhere, could you provide a link?

I noticed this ancient Debian bug report mentioned this error message:
    https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=665487
That's not the same as this situation, but suggests the postrm may have some corner cases that can lead to this error message, depending on order of operations.

Is it possible that dovecot-managesieved was installed, configured, and uninstalled but the unneeded configuration left in place?

I don't think that my prior comment indicating that 'managesieve_notify_capability' is not supported in current dovecot is accurate. I was doing a lot of frantic searching while trying to fix this during/after the upgrade process.

The filesystem that I'm upgrading is old (in that the server was originally setup more than 10 years ago) with continuous hardware and software upgrades since then. It is definitely possible that dovecot-managesieved was installed, configured, and uninstalled but the unneeded configuration left in place?

It is also possible that some files from dovecot-managesieved were left hanging around or that I installed some other old form of sieve management function. (I think that I recall setting it up a long time ago.)

I think that a postrm command missing a corner case is a real possibility.

Thanks for the extra info Bill. Yeah near as I can tell managesieve_notify_capability is still supported if the dovecot-managesieved package is installed. From your explanation it sounds like this could well be a remnant that just happened to not crop up as a problem until the upgrade.

In playing around with installing and uninstalling dovecot-managesieved, current packaging does not appear to modify dovecot.conf anymore. The setting in question is now in:

    /etc/dovecot/conf.d/20-managesieve.conf: #managesieve_notify_capability =

However that's not enabled by installing the package; it's a user configurable item they'd want to review and revise as part of their upgrade.