Basically this:
(Reading database ... 824383 files and directories currently installed.)
Preparing to unpack .../fetchmail_6.6.2-3_amd64.deb ...
Failed to stop fetchmail.service: Unit fetchmail.service not loaded.
dpkg: warning: old fetchmail package prerm maintainer script subprocess failed with exit status 5
dpkg: trying prerm maintainer script from the new fetchmail package instead ...
Failed to stop fetchmail.service: Unit fetchmail.service not loaded.
dpkg: error processing archive /var/cache/apt/archives/fetchmail_6.6.2-3_amd64.deb (--unpack):
new fetchmail package prerm maintainer script subprocess failed with exit status 5
Errors were encountered while processing:
/var/cache/apt/archives/fetchmail_6.6.2-3_amd64.deb
needrestart is being skipped since dpkg has failed
Error: Sub-process /usr/bin/dpkg returned an error code (1)
Currently installed version: 6.6.2-2
However:
$ systemctl disable fetchmail
Failed to disable unit: Unit fetchmail.service does not exist
$ systemctl enable fetchmail
Failed to enable unit: Unit fetchmail.service does not exist
$ wc /usr/lib/systemd/user/fetchmail.service
13 23 288 /usr/lib/systemd/user/fetchmail.service
Best regards,
Eduard.