Sometimes you make some changes to your system and you just know that something will break if a certain package gets updated. You want to keep that certain package from updating until you're ready for it.

In Ubuntu, or any `apt/dpkg` based system, you can tell `apt` to just hold the current package version using `apt-mark hold`. For example, let's say that if the `xxd` package gets updated, it will break something for some reason. Tell `apt` not to update it.

$ sudo apt-mark hold xxd

When you're ready to start updating it again, tell `apt` that it can update it:

$ sudo apt-mark unhold xxd

It's that simple. If you ever want to check what packages are currently in `hold` status, there are two ways to do it.

$ dpkg --get-selections | grep "hold"
xxd                                             hold

$ apt-mark showhold
xxd