diff --git a/.cirrus.yml b/.cirrus.yml
index 453a2ce0ac2c..4ec73ea3f24c 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -39,8 +39,16 @@ task:
         - flutter channel $CHANNEL
         - ./script/incremental_build.sh test
     - name: analyze
+      env:
+        matrix:
+          CHANNEL: "master"
+          CHANNEL: "stable"
       script: ./script/incremental_build.sh analyze
     - name: build_all_plugins_apk
+      env:
+        matrix:
+          CHANNEL: "master"
+          CHANNEL: "stable"
       script:
         # TODO(jackson): Allow web plugins once supported on stable
         # https://github.com/flutter/flutter/issues/42864
@@ -144,6 +152,10 @@ task:
     - xcrun simctl create Flutter-iPhone com.apple.CoreSimulator.SimDeviceType.iPhone-X com.apple.CoreSimulator.SimRuntime.iOS-13-3 | xargs xcrun simctl boot
   matrix:
     - name: build_all_plugins_ipa
+      env:
+        matrix:
+          CHANNEL: "master"
+          CHANNEL: "stable"
       script:
         # TODO(jackson): Allow web plugins once supported on stable
         # https://github.com/flutter/flutter/issues/42864
diff --git a/packages/android_intent/test/android_intent_test.dart b/packages/android_intent/test/android_intent_test.dart
index b0fa48e22fee..ad0eae3b662d 100644
--- a/packages/android_intent/test/android_intent_test.dart
+++ b/packages/android_intent/test/android_intent_test.dart
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// @dart = 2.9
+
 import 'package:android_intent/flag.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -11,7 +13,8 @@ import 'package:platform/platform.dart';
 
 void main() {
   AndroidIntent androidIntent;
-  late MockMethodChannel mockChannel;
+  MockMethodChannel mockChannel;
+
   setUp(() {
     mockChannel = MockMethodChannel();
     when(mockChannel.invokeMethod<bool>('canResolveActivity', any))
diff --git a/packages/flutter_plugin_android_lifecycle/example/integration_test/flutter_plugin_android_lifecycle_test.dart b/packages/flutter_plugin_android_lifecycle/example/integration_test/flutter_plugin_android_lifecycle_test.dart
index 1405ab69153c..ba67043bcf43 100644
--- a/packages/flutter_plugin_android_lifecycle/example/integration_test/flutter_plugin_android_lifecycle_test.dart
+++ b/packages/flutter_plugin_android_lifecycle/example/integration_test/flutter_plugin_android_lifecycle_test.dart
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+// @dart = 2.9
+
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
 import 'package:flutter_plugin_android_lifecycle_example/main.dart';
diff --git a/packages/flutter_plugin_android_lifecycle/example/lib/main.dart b/packages/flutter_plugin_android_lifecycle/example/lib/main.dart
index 6dfe523a0ae1..eb82aacd0237 100644
--- a/packages/flutter_plugin_android_lifecycle/example/lib/main.dart
+++ b/packages/flutter_plugin_android_lifecycle/example/lib/main.dart
@@ -1,3 +1,7 @@
+// Copyright 2019, the Chromium project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 // ignore_for_file: public_member_api_docs
 
 import 'package:flutter/material.dart';
diff --git a/packages/flutter_plugin_android_lifecycle/example/pubspec.yaml b/packages/flutter_plugin_android_lifecycle/example/pubspec.yaml
index 2532ab047dcc..4643317c1951 100644
--- a/packages/flutter_plugin_android_lifecycle/example/pubspec.yaml
+++ b/packages/flutter_plugin_android_lifecycle/example/pubspec.yaml
@@ -1,23 +1,21 @@
 name: flutter_plugin_android_lifecycle_example
 description: Demonstrates how to use the flutter_plugin_android_lifecycle plugin.
-publish_to: 'none'
-
-environment:
-  sdk: ">=2.12.0-0 <3.0.0"
 
 dependencies:
   flutter:
     sdk: flutter
-  integration_test:
-    path: ../../integration_test
+  flutter_plugin_android_lifecycle:
+    path: ../
 
 dev_dependencies:
+  integration_test:
+    path: ../../integration_test
   flutter_test:
     sdk: flutter
   pedantic: ^1.8.0
 
-  flutter_plugin_android_lifecycle:
-    path: ../
+environment:
+  sdk: ">=2.12.0-0 <3.0.0"
 
 flutter:
   uses-material-design: true
diff --git a/packages/local_auth/example/android/app/src/androidTest/java/io/flutter/plugins/localauth/MainActivityTest.java b/packages/local_auth/example/android/app/src/androidTest/java/io/flutter/plugins/localauth/FlutterFragmentActivityTest.java
similarity index 100%
rename from packages/local_auth/example/android/app/src/androidTest/java/io/flutter/plugins/localauth/MainActivityTest.java
rename to packages/local_auth/example/android/app/src/androidTest/java/io/flutter/plugins/localauth/FlutterFragmentActivityTest.java
diff --git a/packages/local_auth/example/lib/main.dart b/packages/local_auth/example/lib/main.dart
index 06e33b9853be..241593a08b6a 100644
--- a/packages/local_auth/example/lib/main.dart
+++ b/packages/local_auth/example/lib/main.dart
@@ -21,16 +21,17 @@ class MyApp extends StatefulWidget {
 
 class _MyAppState extends State<MyApp> {
   final LocalAuthentication auth = LocalAuthentication();
-  bool _canCheckBiometrics;
-  List<BiometricType> _availableBiometrics;
+  late bool _canCheckBiometrics;
+  late List<BiometricType> _availableBiometrics;
   String _authorized = 'Not Authorized';
   bool _isAuthenticating = false;
 
   Future<void> _checkBiometrics() async {
-    bool canCheckBiometrics;
+    late bool canCheckBiometrics;
     try {
       canCheckBiometrics = await auth.canCheckBiometrics;
     } on PlatformException catch (e) {
+      canCheckBiometrics = false;
       print(e);
     }
     if (!mounted) return;
@@ -41,10 +42,11 @@ class _MyAppState extends State<MyApp> {
   }
 
   Future<void> _getAvailableBiometrics() async {
-    List<BiometricType> availableBiometrics;
+    late List<BiometricType> availableBiometrics;
     try {
       availableBiometrics = await auth.getAvailableBiometrics();
     } on PlatformException catch (e) {
+      availableBiometrics = <BiometricType>[];
       print(e);
     }
     if (!mounted) return;
diff --git a/packages/local_auth/example/pubspec.yaml b/packages/local_auth/example/pubspec.yaml
index 0861c51adbc6..9c7b91e672e6 100644
--- a/packages/local_auth/example/pubspec.yaml
+++ b/packages/local_auth/example/pubspec.yaml
@@ -18,5 +18,5 @@ flutter:
   uses-material-design: true
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.12.0-0 <3.0.0"
   flutter: ">=1.12.13+hotfix.5 <2.0.0"
diff --git a/packages/local_auth/integration_test/local_auth_test.dart b/packages/local_auth/integration_test/local_auth_test.dart
index 47e5dfa67912..c09810032461 100644
--- a/packages/local_auth/integration_test/local_auth_test.dart
+++ b/packages/local_auth/integration_test/local_auth_test.dart
@@ -1,3 +1,9 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// @dart = 2.9
+
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
 
diff --git a/packages/share/integration_test/share_test.dart b/packages/share/integration_test/share_test.dart
index 08a19ce2c27b..7b66480d0681 100644
--- a/packages/share/integration_test/share_test.dart
+++ b/packages/share/integration_test/share_test.dart
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+// @dart = 2.9
+
 import 'package:flutter_test/flutter_test.dart';
 import 'package:share/share.dart';
 import 'package:integration_test/integration_test.dart';
diff --git a/packages/share/test/share_test.dart b/packages/share/test/share_test.dart
index fa9f980beae3..d00867b19452 100644
--- a/packages/share/test/share_test.dart
+++ b/packages/share/test/share_test.dart
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// @dart = 2.9
+
 import 'dart:io';
 import 'dart:ui';
 
@@ -15,7 +17,7 @@ import 'package:flutter/services.dart';
 void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
 
-  late MockMethodChannel mockChannel;
+  MockMethodChannel mockChannel;
 
   setUp(() {
     mockChannel = MockMethodChannel();
diff --git a/packages/webview_flutter/CHANGELOG.md b/packages/webview_flutter/CHANGELOG.md
index 19cacb6a6e90..867ea1757985 100644
--- a/packages/webview_flutter/CHANGELOG.md
+++ b/packages/webview_flutter/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 2.0.0-nullsafety.3
+
+* Fix `onWebResourceError` on iOS.
+
 ## 2.0.0-nullsafety.2
 
 * Fix outdated links across a number of markdown files ([#3276](https://github.com/flutter/plugins/pull/3276))
diff --git a/packages/webview_flutter/example/integration_test/webview_flutter_test.dart b/packages/webview_flutter/example/integration_test/webview_flutter_test.dart
index 86cf8ab73e05..5f39cc3d86d2 100644
--- a/packages/webview_flutter/example/integration_test/webview_flutter_test.dart
+++ b/packages/webview_flutter/example/integration_test/webview_flutter_test.dart
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+// @dart = 2.9
+
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
@@ -358,12 +360,12 @@ void main() {
       videoTestBase64 = base64Encode(const Utf8Encoder().convert(videoTest));
     });
 
-    test('Auto media playback', () async {
+    testWidgets('Auto media playback', (WidgetTester tester) async {
       Completer<WebViewController> controllerCompleter =
           Completer<WebViewController>();
       Completer<void> pageLoaded = Completer<void>();
 
-      await pumpWidget(
+      await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: WebView(
@@ -390,7 +392,7 @@ void main() {
       pageLoaded = Completer<void>();
 
       // We change the key to re-create a new webview as we change the initialMediaPlaybackPolicy
-      await pumpWidget(
+      await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: WebView(
@@ -414,15 +416,16 @@ void main() {
 
       isPaused = await controller.evaluateJavascript('isPaused();');
       expect(isPaused, _webviewBool(true));
-    });
+    }, skip: true /* https://github.com/flutter/flutter/issues/72572 */);
 
-    test('Changes to initialMediaPlaybackPolicy are ignored', () async {
+    testWidgets('Changes to initialMediaPlaybackPolicy are ignored',
+        (WidgetTester tester) async {
       final Completer<WebViewController> controllerCompleter =
           Completer<WebViewController>();
       Completer<void> pageLoaded = Completer<void>();
 
       final GlobalKey key = GlobalKey();
-      await pumpWidget(
+      await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: WebView(
@@ -447,7 +450,7 @@ void main() {
 
       pageLoaded = Completer<void>();
 
-      await pumpWidget(
+      await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: WebView(
@@ -472,14 +475,15 @@ void main() {
 
       isPaused = await controller.evaluateJavascript('isPaused();');
       expect(isPaused, _webviewBool(false));
-    });
+    }, skip: true /* https://github.com/flutter/flutter/issues/72572 */);
 
-    test('Video plays inline when allowsInlineMediaPlayback is true', () async {
+    testWidgets('Video plays inline when allowsInlineMediaPlayback is true',
+        (WidgetTester tester) async {
       Completer<WebViewController> controllerCompleter =
           Completer<WebViewController>();
       Completer<void> pageLoaded = Completer<void>();
 
-      await pumpWidget(
+      await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: WebView(
@@ -507,7 +511,7 @@ void main() {
       controllerCompleter = Completer<WebViewController>();
       pageLoaded = Completer<void>();
 
-      await pumpWidget(
+      await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: WebView(
@@ -531,7 +535,7 @@ void main() {
 
       isFullScreen = await controller.evaluateJavascript('isFullScreen();');
       expect(isFullScreen, _webviewBool(true));
-    });
+    }, skip: true /* https://github.com/flutter/flutter/issues/72572 */);
   });
 
   group('Audio playback policy', () {
@@ -631,7 +635,7 @@ void main() {
 
       isPaused = await controller.evaluateJavascript('isPaused();');
       expect(isPaused, _webviewBool(true));
-    });
+    }, skip: true /* https://github.com/flutter/flutter/issues/72572 */);
 
     testWidgets('Changes to initialMediaPlaybackPolocy are ignored',
         (WidgetTester tester) async {
@@ -700,7 +704,7 @@ void main() {
 
       isPaused = await controller.evaluateJavascript('isPaused();');
       expect(isPaused, _webviewBool(false));
-    });
+    }, skip: true /* https://github.com/flutter/flutter/issues/72572 */);
   });
 
   testWidgets('getTitle', (WidgetTester tester) async {
diff --git a/packages/webview_flutter/example/lib/main.dart b/packages/webview_flutter/example/lib/main.dart
index 2a4b652d2658..c7f42ac2bf66 100644
--- a/packages/webview_flutter/example/lib/main.dart
+++ b/packages/webview_flutter/example/lib/main.dart
@@ -105,7 +105,7 @@ class _WebViewExampleState extends State<WebViewExample> {
           if (controller.hasData) {
             return FloatingActionButton(
               onPressed: () async {
-                final String url = await controller.data.currentUrl();
+                final String url = (await controller.data!.currentUrl())!;
                 // ignore: deprecated_member_use
                 Scaffold.of(context).showSnackBar(
                   SnackBar(content: Text('Favorited $url')),
@@ -145,25 +145,25 @@ class SampleMenu extends StatelessWidget {
           onSelected: (MenuOptions value) {
             switch (value) {
               case MenuOptions.showUserAgent:
-                _onShowUserAgent(controller.data, context);
+                _onShowUserAgent(controller.data!, context);
                 break;
               case MenuOptions.listCookies:
-                _onListCookies(controller.data, context);
+                _onListCookies(controller.data!, context);
                 break;
               case MenuOptions.clearCookies:
                 _onClearCookies(context);
                 break;
               case MenuOptions.addToCache:
-                _onAddToCache(controller.data, context);
+                _onAddToCache(controller.data!, context);
                 break;
               case MenuOptions.listCache:
-                _onListCache(controller.data, context);
+                _onListCache(controller.data!, context);
                 break;
               case MenuOptions.clearCache:
-                _onClearCache(controller.data, context);
+                _onClearCache(controller.data!, context);
                 break;
               case MenuOptions.navigationDelegate:
-                _onNavigationDelegateExample(controller.data, context);
+                _onNavigationDelegateExample(controller.data!, context);
                 break;
             }
           },
@@ -299,7 +299,7 @@ class NavigationControls extends StatelessWidget {
           (BuildContext context, AsyncSnapshot<WebViewController> snapshot) {
         final bool webViewReady =
             snapshot.connectionState == ConnectionState.done;
-        final WebViewController controller = snapshot.data;
+        final WebViewController controller = snapshot.data!;
         return Row(
           children: <Widget>[
             IconButton(
diff --git a/packages/webview_flutter/example/pubspec.yaml b/packages/webview_flutter/example/pubspec.yaml
index 543e7fd86971..1ace8afe400f 100644
--- a/packages/webview_flutter/example/pubspec.yaml
+++ b/packages/webview_flutter/example/pubspec.yaml
@@ -2,7 +2,7 @@ name: webview_flutter_example
 description: Demonstrates how to use the webview_flutter plugin.
 
 environment:
-  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+  sdk: ">=2.12.0-0 <3.0.0"
 
 dependencies:
   flutter:
diff --git a/packages/webview_flutter/example/test_driver/integration_test.dart b/packages/webview_flutter/example/test_driver/integration_test.dart
index 7a2c21338786..a8a56aa90f6a 100644
--- a/packages/webview_flutter/example/test_driver/integration_test.dart
+++ b/packages/webview_flutter/example/test_driver/integration_test.dart
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+// @dart = 2.9
+
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
diff --git a/packages/webview_flutter/lib/src/webview_method_channel.dart b/packages/webview_flutter/lib/src/webview_method_channel.dart
index b38d65acb486..54ab647cdc04 100644
--- a/packages/webview_flutter/lib/src/webview_method_channel.dart
+++ b/packages/webview_flutter/lib/src/webview_method_channel.dart
@@ -48,7 +48,8 @@ class MethodChannelWebViewPlatform implements WebViewPlatformController {
           WebResourceError(
             errorCode: call.arguments['errorCode']!,
             description: call.arguments['description']!,
-            failingUrl: call.arguments['failingUrl']!,
+            // iOS doesn't support `failingUrl`.
+            failingUrl: call.arguments['failingUrl'],
             domain: call.arguments['domain'],
             errorType: call.arguments['errorType'] == null
                 ? null
diff --git a/packages/webview_flutter/pubspec.yaml b/packages/webview_flutter/pubspec.yaml
index b2fbfc1110c5..8bdd790e5e36 100644
--- a/packages/webview_flutter/pubspec.yaml
+++ b/packages/webview_flutter/pubspec.yaml
@@ -1,6 +1,6 @@
 name: webview_flutter
 description: A Flutter plugin that provides a WebView widget on Android and iOS.
-version: 2.0.0-nullsafety.2
+version: 2.0.0-nullsafety.3
 homepage: https://github.com/flutter/plugins/tree/master/packages/webview_flutter
 
 environment:
diff --git a/script/build_all_plugins_app.sh b/script/build_all_plugins_app.sh
index f2897f8aa9a2..ca97c05f8ee4 100755
--- a/script/build_all_plugins_app.sh
+++ b/script/build_all_plugins_app.sh
@@ -1,10 +1,16 @@
 #!/bin/bash
 
+#  Usage:
+#
+#   ./script/build_all_plugins_app.sh apk
+#   ./script/build_all_plugins_app.sh ios
+
 # This script builds the app in flutter/plugins/example/all_plugins to make
 # sure all first party plugins can be compiled together.
 
 # So that users can run this script from anywhere and it will work as expected.
 readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" > /dev/null && pwd)"
+
 readonly REPO_DIR="$(dirname "$SCRIPT_DIR")"
 
 source "$SCRIPT_DIR/common.sh"
@@ -23,6 +29,7 @@ readonly EXCLUDED_PLUGINS_LIST=(
   "google_sign_in_platform_interface"
   "google_sign_in_web"
   "image_picker_platform_interface"
+  "local_auth" # flutter_plugin_android_lifecycle conflict
   "instrumentation_adapter"
   "path_provider_linux"
   "path_provider_macos"
@@ -46,7 +53,7 @@ readonly EXCLUDED=$(IFS=, ; echo "${EXCLUDED_PLUGINS_LIST[*]}")
 
 ALL_EXCLUDED=($EXCLUDED)
 # Exclude nnbd plugins from stable.
-if [[ "$CHANNEL" -eq "stable" ]]; then
+if [ "$CHANNEL" == "stable" ]; then
   ALL_EXCLUDED=("$EXCLUDED,$EXCLUDED_PLUGINS_FROM_STABLE")
 fi
 
diff --git a/script/incremental_build.sh b/script/incremental_build.sh
index f54f90b0669c..3911f0a6e9c8 100755
--- a/script/incremental_build.sh
+++ b/script/incremental_build.sh
@@ -16,7 +16,7 @@ fi
 # Plugins that are excluded from this task.
 ALL_EXCLUDED=("")
 # Exclude nnbd plugins from stable.
-if [[ "$CHANNEL" -eq "stable" ]]; then
+if [ "$CHANNEL" == "stable" ]; then
   ALL_EXCLUDED=($EXCLUDED_PLUGINS_FROM_STABLE)
   echo "Excluding the following plugins: $ALL_EXCLUDED"
 fi