For using Rubocop you should install all required gems from gemfiles/linters.gemfile. You can do it like this:
bundle install --gemfile gemfiles/linters.gemfileThis repo is configured for use linters by Pronto under git pre-commit hook see lefthook.yml.
By the way you should also install Lefthook for running linters on only changed files.
WARNING: If you see errors during the installation something with rugged gem and you have macOS.
Please do following:
brew install cmake pkg-config