Thanks for this great effect.
I was very impressed by the demo sounds!
While compiling, it looked for expat, which is not in the readme.
Otoh, I didn't find any packages or libraries matching the string "fluid", except fluidsynth.
I couldn't imagine that's what it needed, so I tried compiling without.
I didn't see any errors or warnings about that, and at least the lv2 seems to work.