The bootstrapping phase works great, even on Windows assuming that you already have a batch like cygwin installed. However I started facing some issues as soon as I added some images in the project.
After adding some images, I got the following error during grunt build :
Error: spawn ENOENT
at errnoException (child_process.js:980:11)
at Process.ChildProcess._handle.onexit (child_process.js:771:34) Use --force to continue.
As it turns out, Grunt does not like jpg files. That is, the imagemin module does not. So, converting those jpg files to png did the trick.