If you can figure out to get our makefile to do that automatically, even better.
Not sure I understand why it was keeping the old one! Shouldn't `$(OCAMLBUILD)` on `src/REPL.ml` run every time and pick up the right inputs... or wait, did I forget entirely to re-make while bisecting? If so, need a `git bisect` for my brain.
I think for the brain, it's called "disect".
But I'm pretty sure the problem is in the tools, because I've seen that same error (which is why I knew what it was about).
Stef