I am sometimes getting an assertion failure that I think should be impossible of this module is implemented correctly:

Fatal error: exception File "lib/frontend/Parse.ml", line 40, characters 9-15: Assertion failed

Unfortunately, I can't narrow down the input that is causing it at the moment because I have been messing with the grammar and I am in an intermediate state. I realise that my changes could be causing this, but I will say that I was getting similar assertion failures before I started messing with the grammar.