Cupertino navigation bar clipping

main.dart

import 'package:flutter/cupertino.dart';

void main() {
  runApp(
    CupertinoApp(
      home: CupertinoPageScaffold(
        navigationBar: CupertinoNavigationBar(
          trailing: CupertinoButton(
            child: Text('Close'),
            onPressed: () {},
          ),
        ),
        child: Text('Hello world'),
      ),
    ),
  );
}