installer cannot find log_err function

Traceback (most recent call last):
File "./db_install.py", line 526, in <module>
   main()
File "./db_install.py", line 477, in main
   user_input(options, prompt_mode=True, pwd=pwd)
File "./db_install.py", line 267, in
  user_input hadoop_discover = HadoopDiscover(cfgs['mgr_user'], cfgs['mgr_pwd'],      cfgs['mgr_url'],cluster_name)
File "/home/centos/python-installer/scripts/common.py", line 166, in _init_self._check_version()
File "/home/centos/python-installer/scripts/common.py", line 220, in _check_version
log_err('Sorry, currently Trafodion doesn\'t support %s version' % self.distro)
NameError: global name 'log_err' is not defined