For me it breaks with or without -break:
ladsgroup@tools-dev:~/core-clean$ python pwb.py welcome -lang:fa
Traceback (most recent call last):
  File "pwb.py", line 157, in <module>
    run_python_file(fn, argv, argvu)
  File "pwb.py", line 67, in run_python_file
    exec(compile(source, filename, "exec"), main_mod.__dict__)
  File "scripts/welcome.py", line 194, in <module>
    locale.setlocale(locale.LC_ALL, '')
  File "/usr/lib/python2.7/locale.py", line 539, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting
<class 'locale.Error'>
CRITICAL: Waiting for 1 network thread(s) to finish. Press ctrl-c to abort