E067: You tried to use the result of a function that doesn't return anything

A function declared with : void doesn’t hand back a value when it finishes – it just does something (like printing a message) and returns to whoever called it. Because there’s genuinely no value produced, you can’t store it, pass it along, or use it in a bigger expression.

Calling a void function on its own line is exactly what it’s for:

fn log_message(msg: string): void {    io::printline(msg);}log_message("hello");   // fine -- just runs it

But trying to grab a value out of it doesn’t work, because there isn’t one:

mut result: string = log_message("hello");

Turf tells you specifically that a void value was used where a real value was expected, along with a bit of context about where that happened.

There are two honest fixes here. If you only ever wanted the side effect (like the printed message) and never actually needed a value back, just call the function as its own statement, without trying to store or use the result. If you genuinely do need a value back, the real fix is upstream: change the function’s own declared return type from void to whatever type it should produce, and add a return statement inside it that actually returns that value.

Run turf --explain E067 in a terminal to read this again.