don't build with Swift Package Manager on stable

.ci/targets/ios_platform_tests.yaml

@@ -9,7 +9,7 @@ tasks:
     script: .ci/scripts/tool_runner.sh
     args: ["fetch-deps", "--ios", "--supporting-target-platforms-only"]
     infra_step: true
-  - name: build examples with Swift Package Manager integration
+  - name: build examples
     script: .ci/scripts/tool_runner.sh
     args: ["build-examples", "--ios", "--swift-package-manager"]
   - name: xcode analyze

.ci/targets/macos_platform_tests.yaml

@@ -6,7 +6,7 @@ tasks:
     script: .ci/scripts/tool_runner.sh
     args: ["fetch-deps", "--macos", "--supporting-target-platforms-only"]
     infra_step: true
-  - name: build examples with Swift Package Manager integration
+  - name: build examples
     script: .ci/scripts/tool_runner.sh
     args: ["build-examples", "--macos", "--swift-package-manager"]
   - name: xcode analyze

script/tool/lib/src/build_examples_command.dart

@@ -135,7 +135,10 @@ class BuildExamplesCommand extends PackageLoopingCommand {
       throw ToolExit(_exitNoPlatformFlags);
     }
 
-    if (usingSwiftPackageManager) {
+    // TODO(vashworth): Enable on stable once Swift Package Manager feature is
+    // available on stable.
+    if (usingSwiftPackageManager &&
+        platform.environment['CHANNEL'] != 'stable') {
       await processRunner.runAndStream(
         flutterCommand,
         <String>['config', '--enable-swift-package-manager'],

script/tool/test/build_examples_command_test.dart

@@ -164,8 +164,11 @@ void main() {
           ]));
     });
 
-    test('building for iOS with Swift Package Manager', () async {
+    test('building for iOS with Swift Package Manager on master channel',
+        () async {
       mockPlatform.isMacOS = true;
+      mockPlatform.environment['CHANNEL'] = 'master';
+
       final RepositoryPackage plugin = createFakePlugin('plugin', packagesDir,
           platformSupport: <String, PlatformDetails>{
             platformIOS: const PlatformDetails(PlatformSupport.inline),
@@ -209,6 +212,50 @@ void main() {
       );
     });
 
+    test(
+        'building for iOS with Swift Package Manager on stable channel does not enable SPM',
+        () async {
+      mockPlatform.isMacOS = true;
+      mockPlatform.environment['CHANNEL'] = 'stable';
+
+      final RepositoryPackage plugin = createFakePlugin('plugin', packagesDir,
+          platformSupport: <String, PlatformDetails>{
+            platformIOS: const PlatformDetails(PlatformSupport.inline),
+          });
+
+      final Directory pluginExampleDirectory = getExampleDir(plugin);
+
+      final List<String> output = await runCapturingPrint(runner, <String>[
+        'build-examples',
+        '--ios',
+        '--enable-experiment=exp1',
+        '--swift-package-manager',
+      ]);
+
+      expect(
+        output,
+        containsAllInOrder(<String>[
+          '\nBUILDING plugin/example for iOS',
+        ]),
+      );
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall(
+            getFlutterCommand(mockPlatform),
+            const <String>[
+              'build',
+              'ios',
+              '--no-codesign',
+              '--enable-experiment=exp1'
+            ],
+            pluginExampleDirectory.path,
+          ),
+        ]),
+      );
+    });
+
     test(
         'building for Linux when plugin is not set up for Linux results in no-op',
         () async {
@@ -306,8 +353,11 @@ void main() {
           ]));
     });
 
-    test('building for macOS with Swift Package Manager', () async {
+    test('building for macOS with Swift Package Manager on master channel',
+        () async {
       mockPlatform.isMacOS = true;
+      mockPlatform.environment['CHANNEL'] = 'master';
+
       final RepositoryPackage plugin = createFakePlugin('plugin', packagesDir,
           platformSupport: <String, PlatformDetails>{
             platformMacOS: const PlatformDetails(PlatformSupport.inline),
@@ -345,6 +395,44 @@ void main() {
       );
     });
 
+    test(
+        'building for macOS with Swift Package Manager on stable channel does not enable SPM',
+        () async {
+      mockPlatform.isMacOS = true;
+      mockPlatform.environment['CHANNEL'] = 'stable';
+
+      final RepositoryPackage plugin = createFakePlugin('plugin', packagesDir,
+          platformSupport: <String, PlatformDetails>{
+            platformMacOS: const PlatformDetails(PlatformSupport.inline),
+          });
+
+      final Directory pluginExampleDirectory = getExampleDir(plugin);
+
+      final List<String> output = await runCapturingPrint(runner,
+          <String>['build-examples', '--macos', '--swift-package-manager']);
+
+      expect(
+        output,
+        containsAllInOrder(<String>[
+          '\nBUILDING plugin/example for macOS',
+        ]),
+      );
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall(
+            getFlutterCommand(mockPlatform),
+            const <String>[
+              'build',
+              'macos',
+            ],
+            pluginExampleDirectory.path,
+          ),
+        ]),
+      );
+    });
+
     test('building for web with no implementation results in no-op', () async {
       createFakePlugin('plugin', packagesDir);