E0005 — Unknown function

A call site names a function that doesn’t exist.

---

What triggers it

Distinct from E0004 because the VM compiler reports this specifically for call positions: f(args) where f isn’t a declared top-level function and isn’t a builtin. Editors surfacing this code can offer “create function” fixes that a generic unknown-identifier error wouldn’t.

Minimal example

fn main() {
    return helper(1);
}

Output:

scratch.rs:2:12: error[E0005]: unknown function `helper`
   return helper(1);
          ^

Fix

Declare the function, import it, or correct the spelling.

fn helper(int n) -> int { return n + 1; }
fn main() {
    return helper(1);
}

Source

Emitted from the VM compiler in resilient/src/compiler.rs.