Appropriate warning when removing important package

[Jeremy Leibs <leibs@willowgarage.com>]

We are attempting to use the debian package system to streamline the
process of setting up the operating system for our software developers
and robotics research platforms.

We have kind of a unique environment in that many of the (somewhat
naive) system users have root-access for installing new packages on an
as-needed basis, but the development environment itself has some
specific requirements.  For example, we require libboost1.37-dev over
libboost-dev.

I have create a trivial deb called "ros-conflicts" which just
explicitly conflicts with the packages we need to avoid.

Unfortunately, when users are doing large apt-get installs, they will
just blindly hit "yes" without thoroughly inspecting the list of
packages which may be removed, putting their system in an unusable
(from a development standpoint) state.

My initial workaround was to just add "Essential: yes" to the
ros-conficts control file so that now users get a much more serious
warning when they try to install a package that conflicts with it.
However, this feels like a misuse of "essential."

Is there a preferred way to present an appropriate warning to people
when a particularly important package is about to be removed?

Thanks,
--Jeremy Leibs