How to install imlib2?

How does one install imlib2?
$ swupd search imlib2
Component imlib2 has version 1.5.1
Although sometimes the above returns:
Search failed, no reasonable results found
I assume this means that imlib2 exists as a package but is not included in any bundles.

$ locate imlib2
no output is generated

This library is needed for openbox which I am attempting to install via building from source.

Cross referencing the GH issue you opened here: