E0038: Raise Requires Effectful

You used the raise keyword with a function call that is not effectful.

Example

fn pure_function() -> i64 {
    42
}

fn main() {
    let x = raise pure_function();  // Error: `raise` can only be used with effectful function calls
}

How to fix

Only use raise with effectful functions, or remove the raise keyword:

fn pure_function() -> i64 {
    42
}

fn main() {
    let x = pure_function();  // OK - no raise needed for pure functions
}