spacemacs, anaconda, jedi/completion: Server error: ValueError('need more than 0 values to unpack',)

Question

my python (2.7.12) code is very simple

import os

os.<HERE>

instead of autocompletion I get following code:

Server error: ValueError('need more than 0 values to unpack',)

but, the following code gives me correct autocompletion.

import sys
sys.<HERE>

I'm running:

emacs-24.5
anaconda_mode-0.1.7
jedi-0.10.0.dist-info
service_factory-0.1.5.dist-info

regards, Mat