syntax_data: {"ast_node_type":"variable","tokens":[{"end":88,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let msg = "found twice-open range pattern (`..`) outside of error recovery";
context_before:         if lo_expr.is_none() && hi_expr.is_none() {
context_after:             self.tcx.dcx().span_bug(span, msg);