Flutter项目iOS工程构建失败 【Undefined symbols for architecture arm64】
错误描述：flutter sdk升级到2.0后构建iOS工程就一直失败，报错的是我的一个扩展工程（app Extension）报错如下：
Undefined symbols for architecture arm64:
“OBJC_CLASS$_FlutterStandardTypedData”, referenced from:
objc-class-ref in flutter_baidu_mapapi_map(BMFMapViewHandles.o)
“OBJC_CLASS$_FlutterStandardMessageCodec”, referenced from:
objc-class-ref in aliyun_video_player(CameraViewFactory.o)
objc-class-ref in flutter_baidu_mapapi_map(BMFMapViewController.o)
“OBJC_CLASS$_FlutterError”, referenced from:
objc-class-ref in aliyun_video_player(CameraView.o)
objc-class-ref in aliyun_video_player(AliyunVideoPlayerPlugin.o)
objc-class-ref in dim(DimPlugin.o)
objc-class-ref in fluwx(FluwxPlugin.o)
objc-class-ref in ios_image_manager(IosImageManagerPlugin.o)
objc-class-ref in iosvideomanager(IosvideomanagerPlugin.o)
objc-class-ref in permission_handler_apple(PermissionHandlerPlugin.o)
…
“OBJC_CLASS$_FlutterMethodChannel”, referenced from:
objc-class-ref in aliyun_video_player(CameraView.o)
objc-class-ref in aliyun_video_player(AliyunVideoPlayerPlugin.o)
objc-class-ref in dim(DimPlugin.o)
objc-class-ref in flutter_baidu_mapapi_base(FlutterBmfbasePlugin.o)
objc-class-ref in flutter_baidu_mapapi_map(BMFMapViewController.o)
objc-class-ref in flutter_baidu_mapapi_map(BMFOfflineMapManager.o)
objc-class-ref in flutter_baidu_mapapi_map(FlutterBmfmapPlugin.o)
…
“OBJC_CLASS$_FlutterEventChannel”, referenced from:
objc-class-ref in aliyun_video_player(AliyunVideoPlayerPlugin.o)
objc-class-ref in aliyun_video_player(VideoPlayerPlugin.o)
objc-class-ref in aliyun_video_player(CameraViewFactory.o)
objc-class-ref in dim(DimPlugin.o)
“_FlutterMethodNotImplemented”, referenced from:
-[CameraView onMethodCall:result:] in aliyun_video_player(CameraView.o)
-[FLTVideoPlayerPlugin handleMethodCall:result:] in aliyun_video_player(VideoPlayerPlugin.o)
-[DimPlugin handleMethodCall:result:] in dim(DimPlugin.o)
-[FlutterBmfbasePlugin handleMethodCall:result:] in flutter_baidu_mapapi_base(FlutterBmfbasePlugin.o)
___83-[BMFMapViewController initWithWithFrame:viewIdentifier:arguments:binaryMessenger:]_block_invoke in flutter_baidu_mapapi_map(BMFMapViewController.o)
-[BMFOfflineMapManager handleMethodCall:result:] in flutter_baidu_mapapi_map(BMFOfflineMapManager.o)
-[FlutterBmfmapPlugin handleMethodCall:result:] in flutter_baidu_mapapi_map(FlutterBmfmapPlugin.o)
…
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
不同项目引入的插件不同，报错也不同但是差不多是这样子的。
问题分析：
字面意思就是链接不到一些仓库，但是我只是修改了flutter的部分，按理说是不应该影响过到原生构建的。
并且报错的是扩展工程，删除扩展工程后主工程是可以正常运行的。
由于自己本身是Android开发，对iOS了解不多所以采用比较原始的方法，创建新的工程再把代码一点一点的添加过去，通过不断对比终于找到问题所在。
解决：
找到如下配置项：
Targets->[app extension] ->build settings ->linking ->other linker flags
删除该选项后项目可以正常运行。
不知道这个配置项是怎么变化的，可能是升级Xcode导致的，也可能是某次构建导致的吧。
如果有知道问题产生原因的人，可以留言给我，谢谢🙏
