docs: def version_cmp(pkg1, pkg2, ignore_epoch=False, **kwargs):  # pylint: disable=unused-argument
      '''
      Do a cmp-style comparison on two packages. Return -1 if pkg1 < pkg2, 0 if
      pkg1 == pkg2, and 1 if pkg1 > pkg2. Return None if there was a problem
      making the comparison.
  
      ignore_epoch : False
          Set to ``True`` to ignore the epoch when comparing versions
  
          .. versionadded:: 2016.3.4
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' pkg.version_cmp '0.2.4-0' '0.2.4.1-0'
      '''
      normalize = lambda x: six.text_type(x).split(':', 1)[-1] if ignore_epoch else six.text_type(x)
      pkg1 = normalize(pkg1)
      pkg2 = normalize(pkg2)
  
      output = __salt__['cmd.run_stdout'](['opkg', '--version'],
                                          output_loglevel='trace',
                                          python_shell=False)
      opkg_version = output.split(' ')[2].strip()
      if salt.utils.versions.LooseVersion(opkg_version) >= \
              salt.utils.versions.LooseVersion('0.3.4'):
          cmd_compare = ['opkg', 'compare-versions']
      elif salt.utils.path.which('opkg-compare-versions'):
          cmd_compare = ['opkg-compare-versions']
      else:
          log.warning('Unable to find a compare-versions utility installed. Either upgrade opkg to '
                      'version > 0.3.4 (preferred) or install the older opkg-compare-versions script.')
          return None
  
      for oper, ret in (("<<", -1), ("=", 0), (">>", 1)):
          cmd = cmd_compare[:]
          cmd.append(_cmd_quote(pkg1))
          cmd.append(oper)
          cmd.append(_cmd_quote(pkg2))
          retcode = __salt__['cmd.retcode'](cmd,
                                            output_loglevel='trace',
                                            ignore_retcode=True,
                                            python_shell=False)
          if retcode == 0:
              return ret
      return None