How to force apt-get to not remove a certain (broken) package on apt-get install --yes --fix-broken

[Andreas Beckmann <anbe@debian.org>]

Dear apt maintainers,

for some piuparts tests piuparts creates a dummy package with the
dependencies of the package to be tested later on to get the test system
into a state where all dependencies are installed except for the package
to be tested subsequently. This is needed for making a snapshot and
afterwards checking whether the tested package modifies anything it
shouldn't.
This dummy package is installed via

    dpkg -i piuparts-depends-dummy.deb
    apt-get -yf install

This works most of the time, but in some cases apt-get considers the
removal of piuparts-depends-dummy as a better solution.

Is there a solution to force apt-get to keep this package installed and
fix up the system at all cost and rather fail if the dependencies cannot
be satisfied?


Andreas