I understand technical limitations and maintenance burden, but I think Rust could be a lot more ergonomic if the borrow checker was applied to functions that don't reference invalid types even if the rest of the codebase contains type errors. I have 146 lifetime errors, some of them very fundamental to the design of my solution, which I didn't spot because the borrow checker wouldn't run until I fixed all totally unrelated type errors in parts of the project that literally only interact with this one through virtual function calls.