錯誤：使用syncdb遷移時，解包需要長度爲4的字符串參數錯誤

Question

從未見過類似的東西。當我在Ubuntu終端上的Django應用程序做python manage.py syncdb，我看到：

error: unpack requires a string argument of length 4

我不知道這意味着什麼或如何解決它。

---

>  Traceback (most recent call last): 
>  File "/home/ubuntu/.virtualenvs/myenv/local/lib/python2.7/site-packages/django/core/management/base.py", 
> line 222, in run_from_argv 
>   self.execute(*args, **options.__dict__) 
>  File "/home/ubuntu/.virtualenvs/myenv/local/lib/python2.7/site-packages/django/core/management/base.py", 
> line 250, in execute 
>   translation.activate('en-us') 
>  File "/home/ubuntu/.virtualenvs/myenv/local/lib/python2.7/site-packages/django/utils/translation/__init__.py", 
> line 90, in activate 
>   return _trans.activate(language) 
>  File "/home/ubuntu/.virtualenvs/myenv/local/lib/python2.7/site-packages/django/utils/translation/trans_real.py", 
> line 183, in activate 
>   _active.value = translation(language) 
>  File "/home/ubuntu/.virtualenvs/myenv/local/lib/python2.7/site-packages/django/utils/translation/trans_real.py", 
> line 172, in translation 
>   default_translation = _fetch(settings.LANGUAGE_CODE) 
>  File "/home/ubuntu/.virtualenvs/myenv/local/lib/python2.7/site-packages/django/utils/translation/trans_real.py", 
> line 133, in _fetch 
>   res = _translation(globalpath) 
>  File "/home/ubuntu/.virtualenvs/myenv/local/lib/python2.7/site-packages/django/utils/translation/trans_real.py", 
> line 127, in _translation 
>   t = gettext_module.translation('django', path, [loc], DjangoTranslation) 
>  File "/usr/lib/python2.7/gettext.py", line 493, in translation 
>   t = _translations.setdefault(key, class_(fp)) 
>  File "/home/ubuntu/.virtualenvs/myenv/local/lib/python2.7/site-packages/django/utils/translation/trans_real.py", 
> line 75, in __init__ 
>   gettext_module.GNUTranslations.__init__(self, *args, **kw) 
>  File "/usr/lib/python2.7/gettext.py", line 180, in __init__ 
>   self._parse(fp) 
>  File "/usr/lib/python2.7/gettext.py", line 273, in _parse 
>   magic = unpack('<I', buf[:4])[0] 
>  error: unpack requires a string argument of length 4 

而且manage.py只包含：

#!/usr/bin/env python 
import os 
import sys 

if __name__ == "__main__": 
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "myapp.settings") 

    from django.core.management import execute_from_command_line 

    execute_from_command_line(sys.argv) 

Answer 1

根據回溯（感謝:)），這個問題從Django中加載其翻譯文件（的Gettext的.mo文件）的莖。

由於magic = unpack('<I', buf[:4])[0]錯誤與「錯誤：解壓縮需要長度爲4的字符串參數」，buf可能短於4個字節。這可能（這裏只是一個假設）意味着有一個截斷的.mo文件在Django試圖加載和失敗的地方。

我建議嘗試重新創建項目的virtualenv，如果這是一個選項 - 或作爲一個創可貼，您可以暫時禁用Django的i18n位。 （USE_I18N = False）