Flutter——CocoaPods not installed

flutter报错如下,可能是因为安装了多个cocoapods.

lib/main.dart:1
Automatically signing iOS for device deployment using specified development team in Xcode project: xxxxxx
Warning: CocoaPods not installed. Skipping pod install.
  CocoaPods is used to retrieve the iOS and macOS platform side's plugin code that responds to your plugin usage on the Dart side.
  Without CocoaPods, plugins will not work on iOS or macOS.
  For more info, see https://flutter.dev/platform-plugins
To install see https://guides.cocoapods.org/using/getting-started.html#installation for instructions.

Exception: CocoaPods not installed or not in valid state.
Exited (sigterm)

解决方法：
1.gem list 可以查看安装的cocoapods版本
2.sudo gem uninstall cocoapods 后选择要卸载的版本
3.卸载了cocoapods后，则
4.转到Flutter项目的iOS目录
5.pod install
重启软件就好了