# Pastebin MDJp0pMK
  (defun rubocop-build-command (command path)
    "Build the full command to be run based on COMMAND and PATH."
    (combine-and-quote-strings
     (nix-shell-command
      (nix-current-sandbox)
      (combine-and-quote-strings
       (append (s-split " " command) (list path))))))

  (defun rubocop-ensure-installed ()
    "Check if RuboCop is installed."
    (nix-executable-find (nix-current-sandbox) "rubocop"))