local variable 'roles' referenced before assignment

[Zambozo]

2018-07-19 07:10:05,122 [salt.loader :764 ][CRITICAL][10950] Failed to load grains defined in grain file ec2_tag_roles.ec2_roles in function <function ec2_roles at 0x29ce0c8>, error:
Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/salt/loader.py", line 757, in grains
ret = funcskey
File "/var/cache/salt/minion/extmods/grains/ec2_tags.py", line 50, in ec2_roles
import os
UnboundLocalError: local variable 'roles' referenced before assignment

Is thos issue only with me ?