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

Question

I'm running Django 1.3 + Python 2.6 on Ubuntu 10.10 (64bit) with uWSGI (0.9.8). However, occasionally I can find some strange 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? This happens not often when traffic is low of when the uwsgi server restarts, and appear much often when the traffic is large and the server runs for a short while.

I'm sure that there is nothing wrong with my django application, but I'm not sure if this is a bug in Django, uWSGI or even Python 2.6.

UPDATE: The latest version of uWSGI doesn't seemed to have this again.

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

Answer 1

Can you try with the latest tip ? It looks like a reference counting bug that should be fixed in 0.9.9-dev

If you can confirm it solves your problem i will release an updated release with only this fix applied.

Many thanks for the report