我有一个颤振项目，我将颤振升级到最新版本。然后突然应用程序停止构建并在问题中给出错误。
我试过了
flutter clean
flutter packages upgrade
flutter packages get
flutter doctor
Flutter 医生显示没有错误
/Users/mac/Desktop/code/flutter/flutter/bin/flutter --no-color doctor
Doctor summary (to see all details, run flutter doctor -v):
[?] Flutter (Channel master, v0.5.6-pre.30, on Mac OS X 10.13.4 17E199, locale en-US)
[?] Android toolchain - develop for Android devices (Android SDK 27.0.3)
[?] iOS toolchain - develop for iOS devices (Xcode 9.3)
[?] Android Studio (version 3.1)
[?] Connected devices (1 available)
• No issues found!
Process finished with exit code …flutter ×1