{"ast_node_type":"variable","tokens":[{"end":86,"kind":"keyword","start":0,"text":"let"}]}
                                        let var_name = self.tcx.hir_name(*var_hir_id);
                                    UpvarMigrationInfo::CapturingPrecise { var_name: captured_name, .. } => {
                                        lint.span_label(closure_head_span, format!("\