just learning about some codegen stuff
The whole concept is pathetic. This is project is meant to be very pathetic. So, if you can't tolerate this level of pathetic projects, run away.
If you want to use the compiler, go to mfbc, and then run cargo build.
Then run the compiler and put brainfuck file. It'll spit c code. TBH, there's no optimizer.
If you want to use the bfvm tool, check mfbc source code to learn how to use this pathetic thing.