Flutter 出现 Pub get failed (server unavailable)问题解决

解决方法

更换国内代理镜像

添加环境变量（用户变量或系统变量都可以）

PUB_HOSTED_URL = https://mirrors.tuna.tsinghua.edu.cn/dart-pub
FLUTTER_STORAGE_BASE_URL = https://mirrors.tuna.tsinghua.edu.cn/flutter

其他镜像

https://flutter.cn/community/china

上海交大 Linux 用户组

PUB_HOSTED_URL = https://dart-pub.mirrors.sjtug.sjtu.edu.cn
FLUTTER_STORAGE_BASE_URL = https://mirrors.sjtug.sjtu.edu.cn

清华大学 TUNA 协会

PUB_HOSTED_URL = https://mirrors.tuna.tsinghua.edu.cn/dart-pub
FLUTTER_STORAGE_BASE_URL = https://mirrors.tuna.tsinghua.edu.cn/flutter

腾讯云开源镜像站

PUB_HOSTED_URL = https://mirrors.cloud.tencent.com/dart-pub
FLUTTER_STORAGE_BASE_URL = https://mirrors.cloud.tencent.com/flutter

官方镜像

PUB_HOSTED_URL = https://pub.flutter-io.cn/
FLUTTER_STORAGE_BASE_URL = https://storage.flutter-io.cn/