// Flat-imported generic struct whose field `y: LocalOnly` names a type that is
// declared only as a BLOCK-LOCAL in the CALLER (`main`). The template's fields
// resolve in THIS module's source context (E3 attempt-4), and a block-local type
// is visible only within its own source, so `LocalOnly` is genuinely undeclared
// here — the source-aware leaf surfaces it instead of binding the caller's local.
Bad :: struct($T: Type) {
    x: T;
    y: LocalOnly;
}