apt-get dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Failed
The following packages have unmet dependencies:
 cron : Depends: upstart-job
 perl : Depends: libdb5.3 but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
E: Internal error, Upgrade broke stuff