diff --git a/bin/internal/engine.version b/bin/internal/engine.version
index 343c1b8..bf8c497 100644
--- a/bin/internal/engine.version
+++ b/bin/internal/engine.version
@@ -1 +1 @@
-ae90085a8437c0ae94d6b5ad2741739ebc742cb4
+2f0af3715217a0c2ada72c717d4ed9178d68f6ed
diff --git a/packages/flutter_tools/lib/src/commands/clean.dart b/packages/flutter_tools/lib/src/commands/clean.dart
index 0caa7df..ba0fc79 100644
--- a/packages/flutter_tools/lib/src/commands/clean.dart
+++ b/packages/flutter_tools/lib/src/commands/clean.dart
@@ -53,6 +53,7 @@
     deleteFile(flutterProject.ios.generatedXcodePropertiesFile);
     deleteFile(flutterProject.ios.generatedEnvironmentVariableExportScript);
     deleteFile(flutterProject.ios.compiledDartFramework);
+    deleteFile(flutterProject.ios.flutterPodspec);
 
     deleteFile(flutterProject.linux.ephemeralDirectory);
     deleteFile(flutterProject.macos.ephemeralDirectory);
diff --git a/packages/flutter_tools/lib/src/macos/build_macos.dart b/packages/flutter_tools/lib/src/macos/build_macos.dart
index 3d29f1a..c45993b 100644
--- a/packages/flutter_tools/lib/src/macos/build_macos.dart
+++ b/packages/flutter_tools/lib/src/macos/build_macos.dart
@@ -98,7 +98,6 @@
       else
         '-quiet',
       'COMPILER_INDEX_STORE_ENABLE=NO',
-      ...environmentVariablesAsXcodeBuildSettings(globals.platform)
     ],
     trace: true,
     stdoutErrorMatcher: verboseLogging ? null : _anyOutput,
diff --git a/packages/flutter_tools/lib/src/project.dart b/packages/flutter_tools/lib/src/project.dart
index 0525247..bc72326 100644
--- a/packages/flutter_tools/lib/src/project.dart
+++ b/packages/flutter_tools/lib/src/project.dart
@@ -652,6 +652,11 @@
       .childDirectory('Flutter')
       .childDirectory('App.framework');
 
+  /// Used only for "flutter clean" to remove old references.
+  File get flutterPodspec => _flutterLibRoot
+      .childDirectory('Flutter')
+      .childFile('Flutter.podspec');
+
   Directory get pluginRegistrantHost {
     return isModule
         ? _flutterLibRoot
diff --git a/packages/flutter_tools/test/commands.shard/hermetic/clean_test.dart b/packages/flutter_tools/test/commands.shard/hermetic/clean_test.dart
index 9a3e62c..fd29f89 100644
--- a/packages/flutter_tools/test/commands.shard/hermetic/clean_test.dart
+++ b/packages/flutter_tools/test/commands.shard/hermetic/clean_test.dart
@@ -49,6 +49,7 @@
         projectUnderTest.ios.generatedXcodePropertiesFile.createSync(recursive: true);
         projectUnderTest.ios.generatedEnvironmentVariableExportScript.createSync(recursive: true);
         projectUnderTest.ios.compiledDartFramework.createSync(recursive: true);
+        projectUnderTest.ios.flutterPodspec.createSync(recursive: true);
 
         projectUnderTest.linux.ephemeralDirectory.createSync(recursive: true);
         projectUnderTest.macos.ephemeralDirectory.createSync(recursive: true);
@@ -69,6 +70,7 @@
         expect(projectUnderTest.ios.generatedXcodePropertiesFile.existsSync(), isFalse);
         expect(projectUnderTest.ios.generatedEnvironmentVariableExportScript.existsSync(), isFalse);
         expect(projectUnderTest.ios.compiledDartFramework.existsSync(), isFalse);
+        expect(projectUnderTest.ios.flutterPodspec.existsSync(), isFalse);
 
         expect(projectUnderTest.linux.ephemeralDirectory.existsSync(), isFalse);
         expect(projectUnderTest.macos.ephemeralDirectory.existsSync(), isFalse);