E0018 — Recursion / stack usage limit exceeded

A function recursed (directly or indirectly) past the interpreter or embedded runtime’s configured stack budget.

---

What triggers it

Deep or unbounded recursion exhausts the call-frame budget before the recursion base case is reached. On the embedded (no_std) runtime this is a fixed static budget checked by rz stack-usage; on the host interpreter/VM it’s the thread stack size.

Minimal example

fn loop_forever(int n) -> int {
    return loop_forever(n + 1);
}
fn main() {
    return loop_forever(0);
}

Output:

scratch.rz:2:12: error[E0018]: recursion limit exceeded in `loop_forever`
    return loop_forever(n + 1);
           ^^^^^^^^^^^^^^^^^^^

Fix

Add a base case that terminates the recursion, or convert the recursion to an explicit loop. For embedded targets, check rz stack-usage against the configured budget.

Source

Emitted from the interpreter/VM call-frame guard in resilient/src/lib.rs, and from the static stack-usage analysis in resilient/src/stack_usage.rs.