I was able to load everything to start using Twitter bootstrap on my ROR application. I even loaded 'therubyracer' gem. Its a windows machine and it seems there are many that have had issues with it.
Comment the following gems in Gemfile
and set the version of twitter-bootstrap-rails
then bundle install
:-
gem "twitter-bootstrap-rails", '2.2.6'
#gem 'therubyracer', :platforms => :ruby
#gem "less-rails" #Sprockets (what Rails 3.1 uses for its asset pipeline) supports LESS
As on windows therubyracer
and less-rails
gems are not required.