libssl-dev cannot be installed

   - [resettest] err: /Stage[main]/Site_nickserver/Package[libssl-dev]/ensure: change from purged to present failed: Execution of '/usr/bin/apt-get -q -y -o DPkg::Options::=--force-confold install libssl-dev' returned 100: Reading package lists...
   - [resettest] Building dependency tree...
   - [resettest] Reading state information...
   - [resettest] Some packages could not be installed. This may mean that you have
   - [resettest] requested an impossible situation or if you are using the unstable
   - [resettest] distribution that some required packages have not yet been created
   - [resettest] or been moved out of Incoming.
   - [resettest] The following information may help to resolve the situation:
   - [resettest] The following packages have unmet dependencies:
   - [resettest]  libssl-dev : Depends: zlib1g-dev but it is not going to be installed
   - [resettest] E: Unable to correct problems, you have held broken packages.

(from redmine: created on 2013-09-09, closed on 2013-09-09, relates #3210)