Debian: Install Packages that were Kept Back

Have you ever seen this message when updating your Debian-based system: "The following packages have been kept back"? Here's why you see it and how to solve it:

You just tried to run the following command:

$ sudo apt-get update && sudo apt-get upgrade --show-upgraded -y

... and you get the message:

The following packages have been kept back

Running apt-get dist-upgrade is dangerous for a stable environment. The wrong source.list setting and you end up with a broken Debian. You might get the entire application upgraded to a version you don't want. For example, the kernel upgrade is kept back. You just want to upgrade the kernel, not the entire distribution.

A better way to handle a kept back package is:

1. sudo aptitude
2. If you have kept back package you should see Upgradable Packages on top of the list.
3. Hit + on that list
4. Hit g twice
5. Answer debconf stuff if asked
6. Press return to continue
7. Press Q to quit
8. Press yes

The kept back packages are now installed.