This repo has a submodule at deps\libal5poly. You will need to sync that
in order to compile this project. My submodule fu is still weak, but I
think something like git clone --recursive' would do the job. Or there's git submodule update' if you've already cloned, I think.
The Makefile is based upon Edgar Reynaldo's MinGW binaries. Adjust as necessary for your environment.
The sample program itself draws 3 circles. They are intended to all be brown. Before drawing the brown circle though I draw a red one. That way if brown isn't loaded as expected then you can visually see where it should have been (to rule out other bugs in the sample).
Read src/main.cpp to understand what it's doing, and check out the fprintf logs to better understand. To be clear, this is likely a bug in libal5poly or in this program, not in Allegro, but I am currently at a loss for finding it. :)