Comment by pmontra

This. Maybe we could call a method of the JIT (it must be exposed) and tell it that we won't use some features of Ruby, globally or inside that scope. That would let it skip some checks. Of course calling that method takes time so it should be something that is called only once. It depends on how the JIT accesses Ruby code.

And if the code actually does what we declared or must not do, we accept any runtime error that it might happen.

We must trust dependencies, including Rails if it's a Rails app.