Flutter在`flutter`命令失败

Question

我正在关注Flutter入门指南并在运行实际flutter命令时卡住:

flutter init -o my_app
Resolving dependencies...
Error on line 17, column 16 of pubspec.yaml: Invalid version constraint: Could not parse version "^1.4.0". Unknown text at "^1.4.0".
  stack_trace: ^1.4.0
               ^^^^^^
Unhandled exception:
Uncaught Error: FileSystemException: Cannot open file, path = '/Users/craig/Code/flutter/packages/flutter_tools/packages/sky_tools/executable.dart' (OS Error: No such file or directory, errno = 2)
Stack Trace:
#0      _File.open.<anonymous closure> (dart:io/file_impl.dart:349)
#1      _RootZone.runUnary (dart:async/zone.dart:1151)
#2      _Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:496)
#3      _Future._propagateToListeners (dart:async/future_impl.dart:579)
#4      _Future._completeWithValue (dart:async/future_impl.dart:339)
#5      _Future._asyncComplete.<anonymous closure> (dart:async/future_impl.dart:401)
#6      _asyncRunCallbackLoop (dart:async/schedule_microtask.dart:41)
#7      _asyncRunCallback (dart:async/schedule_microtask.dart:48)
#8      _runPendingImmediateCallback (dart:isolate-patch/isolate_patch.dart:84)
#9      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:131)

#0      _rootHandleUncaughtError.<anonymous closure> (dart:async/zone.dart:883)
#1      _asyncRunCallbackLoop (dart:async/schedule_microtask.dart:41)
#2      _asyncRunCallback (dart:async/schedule_microtask.dart:48)
#3      _runPendingImmediateCallback (dart:isolate-patch/isolate_patch.dart:84)
#4      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:131)
Unhandled exception:
Uncaught Error: FileSystemException: Cannot open file, path = '/Users/craig/Code/flutter/bin/cache/flutter_tools.snapshot' (OS Error: No such file or directory, errno = 2)
Stack Trace:
#0      _File.open.<anonymous closure> (dart:io/file_impl.dart:349)
#1      _RootZone.runUnary (dart:async/zone.dart:1151)
#2      _Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:496)
#3      _Future._propagateToListeners (dart:async/future_impl.dart:579)
#4      _Future._completeWithValue (dart:async/future_impl.dart:339)
#5      _Future._asyncComplete.<anonymous closure> (dart:async/future_impl.dart:401)
#6      _asyncRunCallbackLoop (dart:async/schedule_microtask.dart:41)
#7      _asyncRunCallback (dart:async/schedule_microtask.dart:48)
#8      _runPendingImmediateCallback (dart:isolate-patch/isolate_patch.dart:84)
#9      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:131)

#0      _rootHandleUncaughtError.<anonymous closure> (dart:async/zone.dart:883)
#1      _asyncRunCallbackLoop (dart:async/schedule_microtask.dart:41)
#2      _asyncRunCallback (dart:async/schedule_microtask.dart:48)
#3      _runPendingImmediateCallback (dart:isolate-patch/isolate_patch.dart:84)
#4      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:131)

Answer 1

看起来你的Dart版本已经过时了< 1.9.2.
尝试dart --version获取已安装的Dart SDK的版本.
目前是1.12.x.

更新2018-03-20

在迁移阶段到Dart 2期间,您可能希望从dev通道安装Dart 以获得2.0.0-alpha.x版本.最新的稳定版本是1.24.x

例如

brew install dart --devel

更新2018-06-21

现在也支持:

brew install dart@2

Answer 2

对于其他遇到类似错误的人，建议您仔细阅读文档。我没有，因此我浪费了很多时间在别处寻找解决方案，即使它一直在我眼前：https : //flutter.io/setup-macos/#update-your-path

我正在写下命令，以便您可以轻松地将它们复制并粘贴到终端窗口中：

touch $HOME/.bash_profile
open $HOME/.bash_profile

第1行创建一个名为的文本文件.bash_profile。第2行将其打开。

然后，下面给出的行必须粘贴到文本文件中：

export PATH=[PATH_TO_FLUTTER_GIT_DIRECTORY]/flutter/bin:$PATH

粘贴后不要忘记保存文件。flutter doctor现在应该可以在每个“终端”窗口中使用。