{"ast_node_type":"variable","tokens":[{"end":100,"kind":"keyword","start":0,"text":"let"}]}
                let mut err = cx.dcx().struct_span_err(sp, format!("`{path}` wasn't a utf-8 file"));
            Err(utf8err) => {
                utf8_error(cx.source_map(), path.as_str(), None, &mut err, utf8err, &bytes[..]);