A list of gotchas
Capistrano deploy fails with “There was an error in your Gemfile, and Bundler cannot continue.”
However bundling locally is fine.
Even if you have
bundler in your Gemfile it appears that the system version
is used. I had an older 1.1 rc version installed in my system Ruby. Therefore
simply ssh in to the server and update to the latest version:
sudo gem install bundler