Not support ES6 ES6, like let

[chsyzxcv]

Not ES6, like let in latest version ? grunt-contrib-uglify report Unexpected token name «subitem»
for example, for(let subitem in setting)

[XhmikosR]

#482 (comment)

[alexlamsl]

Use harmony branch which supports up to ES8.

[chsyzxcv]

hi alexlamsl ,
Thank you so much for your reply. how can we install harmony branch by using npm?
npm install grunt-contrib-uglify --save-dev

[chsyzxcv]

hi alexlamsl,
i had successfully install harmony version . It's work perfectly. Thank you so much
npm install git://github.com/gruntjs/grunt-contrib-uglify.git#harmony