Problem

Builtin and the engine need to be kept in sync. When they aren't, you get cryptic errors. Such as this one: #16317, or main menu errors.

Solutions

Have some sort of version check in builtin. (Or conversely: Declare the builtin version in builtin and have the C++ check that against the C++ version.)

I'm not yet sure how to best do this without introducing another release chore. We can probably shove it into bump_version?

Alternatives

Try to find out how they get out-of-sync, and try to patch that; but often this may be out of our control (e.g. a package being poorly maintained)

Additional context

Main menu instance of this: #16117