错误：SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode

node版本低，node5.0在文件第一行加　”use strict”，或者更新node

brew upgrade node#更新node

curl -sL https://deb.nodesource.com/setup_6.x | bash –

apt-get install nodejs

错误：cross-env NODE_ENV=development webpack –watch –progress –hide-modules –config=node_modules/laravel-mix/setup/webpack.config.js

npm rebuild node-sass

npm run dev#successfully