NameError for built-in Python functions in Django when working with uWSGI

[hust.zcheng@…]

I'm running Django 1.3 on Ubuntu 10.10 (64bit) with uWSGI (0.9.8). However, occasionally I can find such logs in uwsgi.log, reporting that 'getattr', 'isinstance' is not defined. But aren't they Python's built-in functions? Why Django unable to find them? The heavier the traffic is, the more likely this will happend.

I'm sure that there is nothing wrong with my application, but I'm not sure if this is a bug in Django or uWSGI. Can anyone give me a help?

Detail log:

Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/apport_python_hook.py", line 48, in apport_excepthook
    if not enabled():
  File "/usr/lib/python2.6/dist-packages/apport_python_hook.py", line 24, in enabled
    return re.search('^\s*enabled\s*=\s*0\s*$', conf, re.M) is None
  File "/usr/lib/python2.6/re.py", line 142, in search
    return _compile(pattern, flags).search(string)
  File "/usr/lib/python2.6/re.py", line 236, in _compile
    if isinstance(pattern, _pattern_type):
NameError: global name ''''isinstance'''' is not defined

Original exception was:
Traceback (most recent call last):
  File "/usr/local/lib/python2.6/dist-packages/django/core/handlers/wsgi.py", line 258, in __call__
    set_script_prefix(base.get_script_name(environ))
  File "/usr/local/lib/python2.6/dist-packages/django/core/handlers/base.py", line 239, in get_script_name
    if settings.FORCE_SCRIPT_NAME is not None:
  File "/usr/local/lib/python2.6/dist-packages/django/utils/functional.py", line 277, in __getattr__
    return getattr(self._wrapped, name)
NameError: global name 'getattr' is not defined
Traceback (most recent call last):
  File "/usr/local/lib/python2.6/dist-packages/django/core/handlers/wsgi.py", line 258, in __call__
    set_script_prefix(base.get_script_name(environ))
  File "/usr/local/lib/python2.6/dist-packages/django/core/handlers/base.py", line 252, in get_script_name
    return force_unicode(environ.get('SCRIPT_NAME', u''))
  File "/usr/local/lib/python2.6/dist-packages/django/utils/encoding.py", line 64, in force_unicode
    if isinstance(s, unicode):
NameError: global name ''''isinstance'''' is not defined
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/apport_python_hook.py", line 48, in apport_excepthook
    if not enabled():
  File "/usr/lib/python2.6/dist-packages/apport_python_hook.py", line 24, in enabled
    return re.search('^\s*enabled\s*=\s*0\s*$', conf, re.M) is None
  File "/usr/lib/python2.6/re.py", line 142, in search
    return _compile(pattern, flags).search(string)
  File "/usr/lib/python2.6/re.py", line 236, in _compile
    if isinstance(pattern, _pattern_type):
NameError: global name ''''isinstance'''' is not defined

[Jannis Leidel]

This needs a bit more information to ascertain the reasons for the NameError.