buffer.js:321
length += list[i].length;
^
TypeError: Cannot read property 'length' of undefined
at Function.Buffer.concat (buffer.js:321:24)
at /Users/neil/clients/skeleton/local/app/node_modules/gulp-d3r-bundle/index.js:93:46
at /Users/neil/clients/skeleton/local/app/node_modules/gulp-d3r-bundle/index.js:70:30
at FSReqWrap.readFileAfterClose [as oncomplete] (fs.js:445:3)