{"ast_node_type":"other","tokens":[{"end":88,"kind":"keyword","start":0,"text":"struct_span_code_err!(self.dcx(),"}]}
        struct_span_code_err!(self.dcx(), span, E0384, "cannot assign {} {}", msg, desc)
        let msg = if is_arg { "to immutable argument" } else { "twice to immutable variable" };
    }