Run the command in context of the bundle

$ bundle exec [--keep-file-descriptors] <command>

This command executes the command, making all gems specified in the Gemfile(5) available to require in Ruby programs. Essentially, if you would normally have run something like rspec spec/my_spec.rb, and you want to use the gems specified in the Gemfile and installed via bundle install, you should run bundle exec rspec spec/my_spec.rb. Note that bundle exec does not require that an executable is available on your shell's $PATH.