TypeError: Cannot read property 'stripCss' of null
at cleanCss (/media/data/dev-js/hcqh/node_modules/polyclean/index.js:150:24)
at /media/data/dev-js/hcqh/node_modules/lazypipe/index.js:27:19
at Array.map (native)
at build (/media/data/dev-js/hcqh/node_modules/lazypipe/index.js:26:37)
at module.exports (/media/data/dev-js/hcqh/node_modules/polybuild/index.js:60:3)
at Gulp.<anonymous> (/media/data/dev-js/hcqh/gulpfile.js:164:9)
...
(source: https://github.com/duongphuhiep/hcqh/blob/master/gulpfile.js#L164)
gives