locale.Error on mac os x

[sdfsdhgjkbmnmxc]

bash-3.2$ wl
Traceback (most recent call last):
File "/usr/local/bin/wl", line 3, in
from writelightly.main import main
File "/Library/Python/2.7/site-packages/writelightly/main.py", line 10, in
from writelightly.tags import show_tags, show_tag
File "/Library/Python/2.7/site-packages/writelightly/tags.py", line 14, in
locale.setlocale(locale.LC_ALL, ('en_US', 'UTF-8'))
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/locale.py", line 531, in setlocale
return _setlocale(category, locale)
locale.Error: unsupported locale setting