执行flutter run的时候报错，
chenhaodeMac:tudou_app chenhao$ flutter run
Downloading Dart SDK from Flutter engine c4229bfbbae455ad69c967be19aee3fadd6486e1...
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- 0:03:36 --:--:-- 0
curl: (35) LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to storage.googleapis.com:443
Failed to retrieve the Dart SDK from: https://storage.googleapis.com/flutter_infra/flutter/c4229bfbbae455ad69c967be19aee3fadd6486e1/dart-sdk-darwin-x64.zip
If you're located in China, please see this page:
https://flutter.dev/community/china
解决办法
执行flutter doctor之前，先执行一下命令
export PUB_HOSTED_URL=https://pub.flutter-io.cn
export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn
执行结果
chenhaodeMac:tudou_app chenhao$ flutter doctor
Downloading Dart SDK from Flutter engine c4229bfbbae455ad69c967be19aee3fadd6486e1...
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 205M 100 205M 0 0 8165k 0 0:00:25 0:00:25 --:--:-- 7615k
Building flutter tool...
Flutter assets will be downloaded from https://storage.flutter-io.cn. Make sure you trust this
source!
Downloading package sky_engine... 0.6s
Downloading flutter_patched_sdk tools... 2.0s
Downloading flutter_patched_sdk_product tools... 1.2s
Downloading darwin-x64 tools... 3.8s
Downloading darwin-x64/font-subset tools... 1.7s
Downloading android-arm-profile/darwin-x64 tools... 3.9s
Downloading android-arm-release/darwin-x64 tools... 10.6s
Downloading android-arm64-profile/darwin-x64 tools... 2.8s
Downloading android-arm64-release/darwin-x64 tools... 3.0s
Downloading android-x64-profile/darwin-x64 tools... 0.8s
Downloading android-x64-release/darwin-x64 tools... 4.5s
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, v1.14.6, on Mac OS X 10.15.3 19D76, locale zh-Hans-CN)
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
[✓] Xcode - develop for iOS and macOS (Xcode 11.3.1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 3.5)
[✓] VS Code (version 1.42.1)
[✓] Connected device (3 available)
• No issues found!