... A maybe silly but obvious idea: why not remove all the dependencies from mp-community-pr and instead have according "apt-get install" lines for each package in mp-community-pr's postinstall script? We could even add some fancy checks of a well-defined file like /.mp-community-pr_exclude_packages, to allow user to explicitly _not_ install certain stuff she doesn't want to get touched by CSSU upgrades. .../j