I encountered some errors trying to build the program on my own. Meson was failing, saying that the "imagequant" dependency couldn't be found. I'll skip all the diagnostic steps I jumped through and cut to the chase: to compile the program I needed to build and install libimagequant, not the latest version but specifically the 2.x version (when it was still a pure C library).
The solution is pretty straightforward once you know what to do, but it is not documented in the install instructions. The readme should be updated to include mention of this.