I create a new rails project,and add
gem \'bootstrap-sass\'
to my Gemfile, then I run bundle install
and every things going good.
Remove all the comments at the top of the application.css and rename application.css to either application.sass or application.css.scss depending on how you want to do your css'ing Then add:
@import 'bootstrap'
This should allow you to start using bootstrap, providing you have indeed included the bootstrap-sass gem correctly and ran bundle install afterwards.