Should ucf be of priority required?

[Patrick Schoenfeld <schoenfeld@debian.org>]

Hi,

when testing my packages with piuparts I noticed an inability of
our package management. Dpkg does not have support for management
of dynamically generated configuration files. Therefore some packages
now use ucf.

The basic usage is somewhat like
- Registering config files to ucf on installation
- Using it when configuring the package to merge configuration updates
  and local changes
- Unregistering config files to ucf on purge

The crux is the last point. For a good reason postrm must not require
tools it depends on to be around when removing the package itself.
So the call of ucf looks something like that:

    if which ucf >/dev/null; then
        ucf --purge /etc/foo.conf
    fi    

That is okay, as long as ucf is around. But as soon as it isn't
the purge of a package is succesful while leaving modified files around.
So the effect is that a purge does not "remove everything".

Do we really want that? Should ucf be 'required' to avoid that?

Best Regards,
Patrick