Sentry-python: DjangoIntegration conflict with MiddlewareMixin & TemplateView

[cachance7]

django version: 3.0
sentry-sdk version: 0.14.3

My project has a middleware using Django's django.utils.deprecation.MiddlewareMixin. Visiting a view which subclasses django.views.generic.TemplateView while Sentry is active results in the following exception:

AttributeError: 'function' object has no attribute '__self__'
  File "django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "django/core/handlers/base.py", line 196, in _get_response
    middleware_method.__self__.__class__.__name__,

The following classes & url config should be sufficient to demonstrate the problem:

from django.utils.deprecation import MiddlewareMixin
from django.views.generic import TemplateView

# ...in myapp.middleware.py
class DemonstratesConflictMiddleware(MiddlewareMixin):
    def process_template_response(self, request, response):
        return response

# ...in myapp.views.py
class DemonstratesConflictView(TemplateView): 
    template_name = "index.html"


# ...in urls.py
import myapp.views
urlpatterns += [
    path('/', myapp.views.DemonstratesConflictView.as_view(), name='throws-exception'),
]

# ... in settings.py

MIDDLEWARE += ['myapp.middleware.DemonstratesConflictMiddleware']

sentry_sdk.init(
    dsn="OMITTED",
    integrations=[DjangoIntegration()],
)

[untitaker]

Sorry for the slow response, I will look into this now

[untitaker]

Sorry, can't reproduce. Can you provide a template that exhibits this issue?

[untitaker]

Closing due to lack of activity, please respond so we can continue investigating

[kmmbvnr]

@untitaker I've got the same error. With custom middleware with process_template_response and sentry enabled

[untitaker]

Can you provide a minimal self-contained example so I can reproduce this? I
already tried it once and clearly there is more to it than what is
described in the issue.

On Fri, Jul 31, 2020, 06:15 Mikhail Podgurskiy [e-mail]
wrote:

@untitaker https://github.com/untitaker I've got the same error. With
custom middleware with process_template_response and sentry enabled

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[kmmbvnr]

Here is the simple gist. I've added only new style custom middleware with process_template_response method

git clone https://gist.github.com/8760daf908e58a600af4b5ad623fd3e5.git sentry-bug
cd sentry-bug
poetry install
poetry run python ./manage.py runserver

Access to http://127.0.0.1:8000/

Django version 3.1rc1, using settings 'settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
Internal Server Error: /login/
Traceback (most recent call last):
  File "/tmp/sentry-bug/.venv/lib/python3.6/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "/tmp/sentry-bug/.venv/lib/python3.6/site-packages/django/core/handlers/base.py", line 198, in _get_response
    middleware_method.__self__.__class__.__name__,
AttributeError: 'function' object has no attribute '__self__'

Without sentry.init in settings.py the sample works correctly and shows login page

[untitaker]

excellent, thank you

[untitaker]

yes, so the crucial information missing from op was that this can only be reproduced using 3.1, which is not what you get with pip install django. I've posted a PR. Why do people use pre-release versions?

[untitaker]

0.16.3 is out which fixes the problem.

[memclutter]

Not fixed in 0.16.2