Dear Martin, It turns out that it is a bug in dpkg (<https://bugs.debian.org/886389>)…
I tried dpkg-maintscript-helper with `rm_conffile /etc/mime.types` but as a result the upgrade from Buster to Bullseye would ignore local modifications. I will keep this bug open in case there is a chance to do the cleanup in the Bullseye to Bookworm upgrade. Have a nice day, Charles -- Charles Plessy Nagahama, Yomitan, Okinawa, Japan Debian Med packaging team http://www.debian.org/devel/debian-med Tooting from work, https://mastodon.technology/@charles_plessy Tooting from home, https://framapiaf.org/@charles_plessy