code: def _config_hint_generate(optname, both_env_and_param):
      
      env = optname.replace('-', '_').upper()
  
      if both_env_and_param:
          option = '--' + optname.lower()
          return ('Pass "{0}" or set the environment variable "{1}".'
                  .format(option, env))
      else:
          return 'Set the environment variable {0}.'.format(env)
docs: Generate HINT language for missing configuration