in lib/src/shell_words.dart [142:148]
void _checkUnmatchedQuote(StringScanner scanner, int openingQuote) {
if (!scanner.isDone) return;
final type = scanner.substring(openingQuote, openingQuote + 1) == '"'
? 'double'
: 'single';
scanner.error('Unmatched $type quote.', position: openingQuote, length: 1);
}