{"ast_node_type":"variable","tokens":[{"end":91,"kind":"keyword","start":0,"text":"let"}]}
                    let mir::SourceInfo { mut span, scope } = *frame.body.source_info(loc);
                    // If the stacktrace passes through MIR-inlined source scopes, add them.
                    let mut scope_data = &frame.body.source_scopes[scope];