在升级elementui为2.15.7版本后，报以下错误，是因为没有安装sass模块，在package.json中添加sass版本为1.33.0后，运行npm i 安装即可
`98% after emitting CopyPlugin
ERROR Failed to compile with 1 error 10:31:42 ├F10: PM┤
error in ./src/styles/element-variables.scss
Syntax Error: SassError: Undefined function.
╷
490 │ $--group-option-flex: 0 0 math.div(1, 5) * 100% !default;
│ ^^^^^^^^^^^^^^
╵
node_modules\element-ui\packages\theme-chalk\src\common\var.scss 490:27 @import
node_modules\element-ui\packages\theme-chalk\src\mixins\mixins.scss 2:9 @import
node_modules\element-ui\packages\theme-chalk\src\pagination.scss 1:9 @import
E:\前端模板数据\vue-element-admin 版本\集成方案\vue-element-admin-master\src\styles\element-variables.scss 27:9
root stylesheet
@ ./src/styles/element-variables.scss 4:14-237 15:3-20:5 16:22-245
@ ./src/main.js
@ multi (webpack)-dev-server/client?http://192.168.0.107:9527&sockPath=/sockjs-node (webpack)/hot/dev-server.js ./src/main.js`