Voyage Linux: Dialog Error with Apt
This can happen on other Linux distributions, however, in this case, I found it on Voyage Linux, which is a Linux distribution for embedded hardware.
Here we are dealing with an annoyance whenever you use apt-get or aptitude.
debconf: unable to initialize frontend: Dialog<br />
debconf: (No usable dialog-like program is installed, so the dialog-based frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 76, <> line 1.)<br />
debconf: falling back to frontend: Readline
Simply install dialog, which is the package it is not finding. This will no longer need the failback to readline.
# apt-get install dialog
Once the dialog package has been installed the issue will no longer occur on subsequent runs of apt-get or aptitude.