docs: def _info(*pkgs):
      '''
      Get all info brew can provide about a list of packages.
  
      Does not do any kind of processing, so the format depends entirely on
      the output brew gives. This may change if a new version of the format is
      requested.
  
      On failure, returns an empty dict and logs failure.
      On success, returns a dict mapping each item in pkgs to its corresponding
      object in the output of 'brew info'.
  
      Caveat: If one of the packages does not exist, no packages will be
              included in the output.
      '''
      cmd = 'info --json=v1 {0}'.format(' '.join(pkgs))
      brew_result = _call_brew(cmd)
      if brew_result['retcode']:
          log.error('Failed to get info about packages: %s',
                    ' '.join(pkgs))
          return {}
      output = salt.utils.json.loads(brew_result['stdout'])
      return dict(zip(pkgs, output))