这是您可能在多个问题中看到的错误。我试图摆脱它，但它仍然不起作用。
这就是错误。

Running "flutter pub get" in testapp...                  
The current Flutter SDK version is 0.0.0-unknown.

Because qr_code_scanner 0.0.13 requires Flutter SDK version ^1.10.0 and no versions of qr_code_scanner match >0.0.13 <0.1.0, qr_code_scanner ^0.0.13 is forbidden.

So, because testapp depends on qr_code_scanner ^0.0.13, version solving failed.
pub get failed (1; So, because testapp depends on qr_code_scanner ^0.0.13, version solving failed.)
exit code 1

字符串
直到昨天，它工作正常，但今天我重新启动我的Mac，然后它开始给我错误。我尝试了flutter clean和flutter update也尝试了一些其他的建议，我发现从GitHub和SO。我删除了bin目录并下载了稳定版本，但它仍然给我VS代码错误。
我觉得医生看起来很好。

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 1.22.4, on Mac OS X 10.15.7 19H2 darwin-x64, locale
    en-IN)
 
[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
[✗] Xcode - develop for iOS and macOS
    ✗ Xcode installation is incomplete; a full installation is necessary for iOS
      development.
      Download at: https://developer.apple.com/xcode/download/
      Or install Xcode via the App Store.
      Once installed, run:
        sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
        sudo xcodebuild -runFirstLaunch
    ✗ CocoaPods not installed.
        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:
        sudo gem install cocoapods
[✓] Android Studio (version 3.1)
[✓] VS Code (version 1.51.1)
[✓] Connected device (1 available)

! Doctor found issues in 1 category.

型
我目前只在Android上工作。因此，Xcode错误可以忽略。

编辑

在另一个问题中，我发现pubspec.lock有错误的Flutter版本。

flutter:
    dependency: "direct main"
    description: flutter
    source: sdk
    version: "0.0.0"

型
我删除了这个文件并运行flutter clean和flutter pub get，但新生成的文件也有相同的细节。