1.设置淘宝代理

yarn config set registry ‘https://registry.npm.taobao.org‘

2.如果网址本地可以打开，说明你本地有代理设置

所以需要按本地的代理 设置yarn访问代理（本地代理查看的话，点检浏览器 inter选项--> 连接 --> 局域网设置 ）

yarn config set proxy http://1.2.1.251

yarn config set https-proxy http://1.2.1.251

Yarn install 报错 Resolving packages... [2/4] Fetching packages... info There appears to be trouble with your network connection. Retrying