Just a heads up, I'm having the same issue but have gotten it further by adding loads of deps to the `bower.json` file: https://github.com/cancerit/proportionalmultibw/compare/feature/webpack?#diff-0a08a7565aba4405282251491979bb6b I've gotten up to this point but can't diagnose it: https://travis-ci.org/cancerit/proportionalmultibw/jobs/400187160#L823