技術標籤：vue-cli-servicevue

專案啟動，報錯如下：

$ vue-cli-service serve
 INFO  Starting development server...
<s> [webpack.Progress] 0% compiling
<s> [webpack.Progress] 10% building 0/0 modules 0 active
<s> [webpack.Progress] 10% building 0/1 modules 1 active multi D:\item\coupon-pc\node_modules\webpack-
 
dev-server\client\index.js?http://10.32.46.125:8080&sockPath=/sockjs-node D:\item\coupon-pc\node_modules\webpack\hot\dev-server.js ./src/main.js
<s> [webpack.Progress] 10% building 1/1 modules 0 active
<s> [webpack.Progress] 10% building 1/1 modules 0 active
<s> [webpack.Progress] 10% building 1
 
/2 modules 1 active multi D:\item\coupon-pc\node_modules\webpack\hot\dev-server.js D:\item\coupon-pc\node_modules\webpack-dev-server\client\index.js?http://10.32.46.125:8080&sockPath=/sockjs-node ./src/main.js
<s> [webpack.Progress] 10% building 2/2 modules 0 active
 ERROR  TypeError: Cannot read property 'upgrade'
 
 of undefined
TypeError: Cannot read property 'upgrade' of undefined
    at Server.<anonymous> (D:\item\coupon-pc\node_modules\webpack-dev-server\lib\Server.js:135:47)
    at Array.forEach (<anonymous>)
    at new Server (D:\item\coupon-pc\node_modules\webpack-dev-server\lib\Server.js:134:27)
    at serve (D:\item\coupon-pc\node_modules\@vue\cli-service\lib\commands\serve.js:172:20)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

原因：vue.config.js檔案配置，代理地址為空導致，修改target即可。