我正在努力开发针对iOS模拟器的Flutter应用程序。我经常看到以下内容：
/.../ios/Pods/SDWebImage/SDWebImage/Core/SDWebImagePrefetcher.h:92:1: Property with 'retain (or strong)' attribute must be of object type
尽管受影响的特定Pod可能会有所不同。有人处理过吗？
我正在使用Xcode版本11.4。
flutter doctor -v的结果：
[✓] Flutter (Channel master, v1.16.4-pre.88, on Mac OS X 10.15.3 19D76, locale en-NZ)
• Flutter version 1.16.4-pre.88 at /Users/sthomas/flutter
• Framework revision ab14307e0c (17 hours ago), 2020-04-03 00:56:01 -0400
• Engine revision f5127cc07a
• Dart version 2.8.0 (build 2.8.0-dev.19.0 fae35fca47)
[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
• Android SDK at /Users/sthomas/Library/Android/sdk
• Platform android-29, build-tools 28.0.3
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)
• All Android licenses accepted.
[✓] Xcode - develop for iOS and macOS (Xcode 11.4)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 11.4, Build version 11E146
• CocoaPods version 1.9.1
[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
[✓] Android Studio (version 3.5)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 43.0.1
• Dart plugin version 191.8593
• Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)
[✓] Connected device (3 available)
• AOSP on IA Emulator • emulator-5554 • android-x86 • Android 9 (API 28) (emulator)
• Chrome • chrome • web-javascript • Google Chrome 80.0.3987.149
• Web Server • web-server • web-javascript • Flutter Tools
• No issues found!