WARNING in configuration The 'mode' option has not been set, webpack will fallback to 'production...

webpack打包时出现下面的报错

WARNING in configuration
The ‘mode’ option has not been set, webpack will fallback to ‘production’ for this value. Set ‘mode’ option to ‘development’ or ‘production’ to enable defaults for each environment.
You can also set it to ‘none’ to disable any default behavior. Learn more: https://webpack.js.org/configuration/mode/

原因:没有设置webpack的模式，是生产还是开发（production or development）

解决方法

webpack --mode=development