Django 1.6 upgrade: "cannot import name BaseHandler"

[Erik Evenson]

I am trying to upgrade from Django 1.5.5 to Django 1.6. Everything tests fine, but when I try to run my django project, I get the following error:

ValueError: Unable to configure handler 'mail_admins': Cannot resolve 'vbenergyzone.core.utils.log.StaffSuperuserEmailHandler': cannot import name BaseHandler

Also: ​http://stackoverflow.com/questions/20167580/django-1-6-upgrade-cannot-import-name-basehandler.

Here is what I have tried:

• I have removed my custom logging handler code completely. The project runs fine without any errors.
• I have replaced my custom logging handler code and replaced it with the default handler code. I get the same error.
• I have tried Django 1.6c1 and get the same error.

Thanks!

Here is my stacktrace:

20:29:03 web.1 | started with pid 1501
20:29:03 worker.1 | started with pid 1504
20:29:03 web.1 | 2013-11-23 20:29:03 [1503] [INFO] Starting gunicorn 18.0
20:29:03 web.1 | 2013-11-23 20:29:03 [1503] [INFO] Listening at: ​http://192.168.50.4:5000 (1503)
20:29:03 web.1 | 2013-11-23 20:29:03 [1503] [INFO] Using worker: sync
20:29:03 web.1 | 2013-11-23 20:29:03 [1518] [INFO] Booting worker with pid: 1518
20:29:04 web.1 | 2013-11-23 14:29:04 [1518] [ERROR] Exception in worker process:
20:29:04 web.1 | Traceback (most recent call last):
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/arbiter.py", line 495, in spawn_worker
20:29:04 web.1 | worker.init_process()
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/workers/base.py", line 106, in init_process
20:29:04 web.1 | self.wsgi = self.app.wsgi()
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/app/base.py", line 114, in wsgi
20:29:04 web.1 | self.callable = self.load()
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py", line 62, in load
20:29:04 web.1 | return self.load_wsgiapp()
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py", line 49, in load_wsgiapp
20:29:04 web.1 | return util.import_app(self.app_uri)
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/util.py", line 354, in import_app
20:29:04 web.1 | import(module)
20:29:04 web.1 | File "/vagrant/vbenergyzone/wsgi.py", line 23, in <module>
20:29:04 web.1 | from django.core.wsgi import get_wsgi_application
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/core/wsgi.py", line 1, in <module>
20:29:04 web.1 | from django.core.handlers.wsgi import WSGIHandler
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/core/handlers/wsgi.py", line 11, in <module>
20:29:04 web.1 | from django.core.handlers import base
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 12, in <module>
20:29:04 web.1 | from django.db import connections, transaction
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/db/init.py", line 83, in <module>
20:29:04 web.1 | signals.request_started.connect(reset_queries)
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/dispatch/dispatcher.py", line 88, in connect
20:29:04 web.1 | if settings.DEBUG:
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/conf/init.py", line 54, in getattr
20:29:04 web.1 | self._setup(name)
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/conf/init.py", line 50, in _setup
20:29:04 web.1 | self._configure_logging()
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/conf/init.py", line 80, in _configure_logging
20:29:04 web.1 | logging_config_func(self.LOGGING)
20:29:04 web.1 | File "/usr/lib/python2.7/logging/config.py", line 777, in dictConfig
20:29:04 web.1 | dictConfigClass(config).configure()
20:29:04 web.1 | File "/usr/lib/python2.7/logging/config.py", line 575, in configure
20:29:04 web.1 | '%r: %s' % (name, e))
20:29:04 web.1 | ValueError: Unable to configure handler 'mail_admins': Cannot resolve 'vbenergyzone.core.utils.log.StaffSuperuserEmailHandler': cannot import name BaseHandler
20:29:04 web.1 | Traceback (most recent call last):
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/arbiter.py", line 495, in spawn_worker
20:29:04 web.1 | worker.init_process()
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/workers/base.py", line 106, in init_process
20:29:04 web.1 | self.wsgi = self.app.wsgi()
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/app/base.py", line 114, in wsgi
20:29:04 web.1 | self.callable = self.load()
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py", line 62, in load
20:29:04 web.1 | return self.load_wsgiapp()
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py", line 49, in load_wsgiapp
20:29:04 web.1 | return util.import_app(self.app_uri)
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/gunicorn/util.py", line 354, in import_app
20:29:04 web.1 | import(module)
20:29:04 web.1 | File "/vagrant/vbenergyzone/wsgi.py", line 23, in <module>
20:29:04 web.1 | from django.core.wsgi import get_wsgi_application
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/core/wsgi.py", line 1, in <module>
20:29:04 web.1 | from django.core.handlers.wsgi import WSGIHandler
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/core/handlers/wsgi.py", line 11, in <module>
20:29:04 web.1 | from django.core.handlers import base
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 12, in <module>
20:29:04 web.1 | from django.db import connections, transaction
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/db/init.py", line 83, in <module>
20:29:04 web.1 | signals.request_started.connect(reset_queries)
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/dispatch/dispatcher.py", line 88, in connect
20:29:04 web.1 | if settings.DEBUG:
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/conf/init.py", line 54, in getattr
20:29:04 web.1 | self._setup(name)
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/conf/init.py", line 50, in _setup
20:29:04 web.1 | self._configure_logging()
20:29:04 web.1 | File "/home/vagrant/.virtualenvs/VBEZ/local/lib/python2.7/site-packages/django/conf/init.py", line 80, in _configure_logging
20:29:04 web.1 | logging_config_func(self.LOGGING)
20:29:04 web.1 | File "/usr/lib/python2.7/logging/config.py", line 777, in dictConfig
20:29:04 web.1 | dictConfigClass(config).configure()
20:29:04 web.1 | File "/usr/lib/python2.7/logging/config.py", line 575, in configure
20:29:04 web.1 | '%r: %s' % (name, e))
20:29:04 web.1 | ValueError: Unable to configure handler 'mail_admins': Cannot resolve 'vbenergyzone.core.utils.log.StaffSuperuserEmailHandler': cannot import name BaseHandler

Here is my logging configuration:

LOGGING = {

'version': 1,
'disable_existing_loggers': True,
'filters': {

'require_debug_false': {

'()': 'django.utils.log.RequireDebugFalse'

}

},

'formatters': {

'verbose': {

'format': '%(levelname)s %(asctime)s %(module)s %(process)d %(thread)d %(message)s'

},
'simple': {

'format': '%(levelname)s %(message)s'

},

},
'handlers': {

'null': {

'level': 'DEBUG',
'class': 'django.utils.log.NullHandler',

},
'console':{

'level': 'DEBUG',
'class': 'logging.StreamHandler',
'formatter': 'simple'

},
'mail_admins': {

'level': 'ERROR',
# 'class': 'django.utils.log.AdminEmailHandler',
'class': 'vbenergyzone.core.utils.log.StaffSuperuserEmailHandler',
'filters': [],

}

},
'loggers': {

'django': {

'handlers': null,
'propagate': True,
'level': 'INFO',

},
'django.request': {

'handlers': mail_admins,
'level': 'ERROR',
'propagate': True,

},
'vbenergyzone': {

'handlers': ['console', 'mail_admins'],
'level': 'INFO',

}

}

}

Here is my custom logger:

"""
Logging utilities
"""
import logging
import traceback

from django.contrib.sites.models import Site

from django.views.debug import get_exception_reporter_filter

from vbenergyzone.core import send_message

# ==============================================================================

class StaffSuperuserEmailHandler(logging.Handler):

def emit(self, record):

try:

request = record.request
domain = Site.objects.get_current().domain

subject = 'User %s experienced an error on %s: %s' % \

(request.user, domain, record.getMessage())

filter = get_exception_reporter_filter(request)
request_repr = filter.get_request_repr(request)

except Exception:

subject = '%s: %s' % (

record.levelname,
record.getMessage(),

)

request = None
request_repr = "Request repr() unavailable."

if record.exc_info:

exc_info = record.exc_info
stack_trace = \

'\n'.join(traceback.format_exception(*record.exc_info))

else:

exc_info = (None, record.getMessage(), None)
stack_trace = 'No stack trace available'

context_object = {

'message': record.getMessage(),
'request': request,
'request_repr': request_repr,
'stack_trace': stack_trace,

}

send_message(

context_object=context_object,
html_template='core/email/staff_super_email_handler.html',
send_to_staff_and_superusers=True,
subject=self.format_subject(subject),
text_template='core/email/staff_super_email_handler.txt',

)

def format_subject(self, subject):

"""
Escape CR and LF characters, and limit length.
RFC 2822's hard limit is 998 characters per line. So, minus "Subject: "
the actual subject must be no longer than 989 characters.
"""
formatted_subject = subject.replace('\n', '
n').replace('\r', '
r')
return formatted_subject[:989]