user5@system:/var/cache/apt/archives$ sudo apt install aptitude
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
 aptitude : Depends: aptitude-common (= 0.7.4-2ubuntu2) but it is not going to be installed
            Depends: libcwidget3v5 but it is not going to be installed
 emacs24 : Depends: emacs24-bin-common (= 24.5+1-6ubuntu1) but 24.5+1-6ubuntu1.1 is to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).