ruby - guard laravel - how can I pass an option to force polling to the listen rubygem -

i using guard-laravel package on project in hope of using sass. unfortunately, using vagrant development environment uses vitualbox shares mount web sites folders vm- unfortunately because appears changes virtualbox shared folders not picked listen rubygem.

this, believe, leaves me 2 options:

1) use samba share folders - option, suspect may bit of pain vagrant/chef play nicely

or

2) force listen rubygem polling mode, have read can pass in flag since not manually launching listen gem dont know how can this.

can suggest how might force gem go polling mode or if know way make listen gem watch shared folders equally wonderful if not wonderfullier.