I made a rails project with,
rails new test_bootstrap.
succeeded.
moved to the project dir and added the gems
gem \
i feel this has less to do with libv8 and more to do with therubyracer.
i received your same error while running a bundle install on a rails app. if you have encountered this similarly, try installing the gem outside of bundle like so:
gem install therubyracer
then run bundle install. i hope this works for you too.