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

1.設置淘寶代理

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

2.如果網址本地可以打開，說明你本地有代理設置

所以需要按本地的代理 設置yarn訪問代理（本地代理查看的話，點檢瀏覽器 inter選項--> 連接 --> 局域網設置 ）

yarn config set proxy http://1.2.1.251

yarn config set https-proxy http://1.2.1.251