With node.js v4.x "gulp-sass" version within Package.json should be moved to "^2.0.0" or system will fail on libsass. Error message is not very explicit:
Loading "sass.js" tasks...ERROR
Error: libsass bindings not found. Try reinstalling node-sass?
Warning: Task "sass" not found. Use --force to continue.
With node.js v4.x "gulp-sass" version within Package.json should be moved to "^2.0.0" or system will fail on libsass. Error message is not very explicit: