This shows up whenever you write a type annotation – on a variable, a function parameter, a return type, or a struct field – and the type name you used doesn’t match anything Turf knows about: not a struct or enum in your file, not one from any module you’ve imported, and not one of the built-in types like int or string either.
Here’s a struct declared correctly and then used correctly:
struct Point { x: int, y: int }mut p: Point = Point::default();And here’s the typo that trips this error:
mut p: Piont = Point::default();// ERROR: Unknown type 'Piont'.As usual, if your typo is close to a real type name, Turf will suggest the one it thinks you meant.
If it’s not a typo, there are two other likely explanations. Maybe the struct or enum just hasn’t been written yet – double check you actually declared it somewhere in the file, above where you’re using it. Or maybe it’s meant to come from a module you haven’t imported – in that case, you’ll usually see a slightly different, more specific error (about the type not being visible without qualification) instead of this one, which tells you exactly which module to import from.
Once the name matches a real, in-scope struct, enum, or builtin type exactly, this error goes away.
Run turf --explain E042 in a terminal to read this again.