issue 91157

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class WidgetThatPrintWhenIsBuilt extends StatelessWidget {
  final String text;
  WidgetThatPrintWhenIsBuilt({
    required this.text,
  }) : super(key: ValueKey('WidgetThatPrintWhenIsBuilt:$text'));

  @override
  Widget build(BuildContext context) {
    print('building "$text"');
    return Text(
      text,
      key: ValueKey(text),
      style: const TextStyle(fontSize: 40),
    );
  }
}

class MyApp extends StatelessWidget {
  const MyApp({
    final key = const ValueKey('MyApp'),
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(home: MyHomePage());
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({
    final key = const ValueKey('MyHomePage'),
  }) : super(key: key);

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  late final ScrollController _controller;
  final _list = [for (var i = 0; i < 40; ++i) i];

  @override
  void initState() {
    super.initState();
    _controller = ScrollController();
  }

  @override
  void dispose() {
    super.dispose();
    _controller.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      key: const ValueKey('Scaffold'),
      body: CustomScrollView(
        key: const ValueKey('CustomScrollView'),
        controller: _controller,
        slivers: [
          SliverList(
            key: const ValueKey('SliverList'),
            delegate: SliverChildBuilderDelegate(
              (context, index) =>
                  WidgetThatPrintWhenIsBuilt(text: '${_list[index]}'),
              childCount: _list.length,
            ),
          )
        ],
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () => setState(() => _list.add(_list.length)),
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}