IL2CPP with JIT-requiring code: When does it report this?

I’ve had a surprisingly hard time finding a concrete answer to this. If I have code in-game that require JIT compilation (some types of XML serializer do this, for example) and switch to an IL2CPP back-end, does it report these problems at compile time? Or does it not say anything until you actually exercise that code?

This seems like something that could be reported at compile time, but maybe I’m niave.

It is not possible to detect code that requires JIT at compile time. If this code is executed, it will cause an error at runtime with IL2CPP.