[Django] #33674: Timezones cause 500 errors to not email the site admin

Django

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May 2, 2022, 7:28:22 PM5/2/22

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#33674: Timezones cause 500 errors to not email the site admin
-------------------------------------------+------------------------
Reporter: iragm | Owner: (none)
Type: Bug | Status: new
Component: Error reporting | Version: 4.0
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------------+------------------------
I believe I have found a bug - my site was working great prior to adding
support for localization/timezones and if a user encountered a 500
internal server error, I'd get an email about it and could fix it. I
added support for timezones, and **stopped getting the alert emails** --
and the users are no longer sent to my 500 page.

Here's some information:
* debug=True causes things to work correctly (no email sent, debug info
displayed to the user)
* this does not happen in a development environment at all as far as I can
tell
* I am using Channels and Daphne to serve content behind an Nginx reverse
proxy
* When 500 errors happen, the user gets redirected to a very generic
Daphne "exception inside application" page. Before you blame this on
Daphne, please keep reading...
* The error log traceback points to `site-
packages/django/templatetags/tz.py`

If I change this class to look as follows:
{{{
def render(self, context):
try:
with timezone.override(self.tz.resolve(context)):
output = self.nodelist.render(context)
return output
except:
return self.nodelist.render(context)
}}}
the correct 500 error page is rendered and the email goes out to me
telling me where the error occurred. That suggests to me that something
in timezone.override isn't working as it should be.

I could just make a PR with this but I am not really sure what
consequences this change has.

I know there's a lack of info in this, and I apologize in advance. Because
I only see this issue on my production server, I have to take my whole
site down to try to test and troubleshoot it.

--
Ticket URL: <https://code.djangoproject.com/ticket/33674>
Django <https://code.djangoproject.com/>
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Django

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May 2, 2022, 7:31:47 PM5/2/22

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#33674: Timezones cause 500 errors to not email the site admin

---------------------------------+--------------------------------------

Reporter: iragm | Owner: (none)
Type: Bug | Status: new
Component: Error reporting | Version: 4.0

Severity: Normal | Resolution:

Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

---------------------------------+--------------------------------------
Description changed by iragm:

Old description:

New description:

I believe I have found a bug - my site was working great prior to adding
support for localization/timezones and if a user encountered a 500
internal server error, I'd get an email about it and could fix it. I
added support for timezones, and **stopped getting the alert emails** --
and the users are no longer sent to my 500 page.

Here's some information:
* debug=True causes things to work correctly (no email sent, debug info
displayed to the user)
* this does not happen in a development environment at all as far as I can
tell
* I am using Channels and Daphne to serve content behind an Nginx reverse
proxy

* Edit: using python3 manage.py runserver with debug=False returns the
correct 500 page. This issue is only happening when running with Daphne.

* When 500 errors happen, the user gets redirected to a very generic
Daphne "exception inside application" page. Before you blame this on
Daphne, please keep reading...
* The error log traceback points to `site-
packages/django/templatetags/tz.py`

If I change this class to look as follows:
{{{
def render(self, context):
try:
with timezone.override(self.tz.resolve(context)):
output = self.nodelist.render(context)
return output
except:
return self.nodelist.render(context)
}}}
the correct 500 error page is rendered and the email goes out to me
telling me where the error occurred. That suggests to me that something
in timezone.override isn't working as it should be.

I could just make a PR with this but I am not really sure what
consequences this change has.

I know there's a lack of info in this, and I apologize in advance. Because
I only see this issue on my production server, I have to take my whole
site down to try to test and troubleshoot it.

--

--
Ticket URL: <https://code.djangoproject.com/ticket/33674#comment:1>

Django

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May 3, 2022, 3:02:35 AM5/3/22

to django-...@googlegroups.com

#33674: Timezones cause 500 errors to not email the site admin
---------------------------------+--------------------------------------
Reporter: iragm | Owner: (none)

Type: Bug | Status: closed

Component: Error reporting | Version: 4.0

Severity: Normal | Resolution: needsinfo

Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
---------------------------------+--------------------------------------

Changes (by Carlton Gibson):

* status: new => closed
* resolution: => needsinfo

Comment:

Hi, thanks for the report.

Can I ask you to flesh it out?

> The error log traceback points to site-
packages/django/templatetags/tz.py

Can you provide the traceback here please? (Specifically, we need to see
what the exception is that you're catching with the added `except`
there...)

Thanks.

--
Ticket URL: <https://code.djangoproject.com/ticket/33674#comment:2>

Django

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May 3, 2022, 6:55:06 AM5/3/22

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#33674: Timezones cause 500 errors to not email the site admin
---------------------------------+--------------------------------------
Reporter: iragm | Owner: (none)
Type: Bug | Status: closed
Component: Error reporting | Version: 4.0
Severity: Normal | Resolution: needsinfo
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
---------------------------------+--------------------------------------

Comment (by iragm):

{{{
2022-05-03 06:47:54,594 ERROR Exception inside application: 'No time
zone found with key '
Traceback (most recent call last):
File "/opt/production/lib/python3.9/site-
packages/django/core/handlers/exception.py", line 42, in inner
response = await get_response(request)
File "/opt/production/lib/python3.9/site-
packages/django/core/handlers/base.py", line 253, in _get_response_async
response = await wrapped_callback(
File "/opt/production/lib/python3.9/site-packages/asgiref/sync.py", line
414, in __call__
ret = await asyncio.wait_for(future, timeout=None)
File "/usr/lib/python3.9/asyncio/tasks.py", line 442, in wait_for
return await fut
File "/opt/production/lib/python3.9/site-
packages/asgiref/current_thread_executor.py", line 22, in run
result = self.fn(*self.args, **self.kwargs)
File "/opt/production/lib/python3.9/site-packages/asgiref/sync.py", line
455, in thread_handler
return func(*args, **kwargs)
File "/opt/production/lib/python3.9/site-
packages/django/views/generic/base.py", line 84, in view
return self.dispatch(request, *args, **kwargs)
File "/opt/production/fishauctions/./auctions/views.py", line 2242, in
dispatch
raise DeliberateError("break stuff")
NameError: name 'DeliberateError' is not defined

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/opt/production/lib/python3.9/site-
packages/django/core/handlers/exception.py", line 42, in inner
response = await get_response(request)
File "/opt/production/lib/python3.9/site-
packages/django/utils/deprecation.py", line 150, in __acall__
response = response or await self.get_response(request)
File "/opt/production/lib/python3.9/site-
packages/django/core/handlers/exception.py", line 44, in inner
response = await sync_to_async(
File "/opt/production/lib/python3.9/site-packages/asgiref/sync.py", line
414, in __call__
ret = await asyncio.wait_for(future, timeout=None)
File "/usr/lib/python3.9/asyncio/tasks.py", line 442, in wait_for
return await fut
File "/usr/lib/python3.9/concurrent/futures/thread.py", line 52, in run
result = self.fn(*self.args, **self.kwargs)
File "/opt/production/lib/python3.9/site-packages/asgiref/sync.py", line
453, in thread_handler
return func(*args, **kwargs)
File "/opt/production/lib/python3.9/site-
packages/django/core/handlers/exception.py", line 139, in
response_for_exception
response = handle_uncaught_exception(
File "/opt/production/lib/python3.9/site-
packages/django/core/handlers/exception.py", line 184, in
handle_uncaught_exception
return callback(request)
File "/opt/production/lib/python3.9/site-
packages/django/utils/decorators.py", line 133, in _wrapped_view
response = view_func(request, *args, **kwargs)
File "/opt/production/lib/python3.9/site-
packages/django/views/defaults.py", line 102, in server_error
return HttpResponseServerError(template.render())
File "/opt/production/lib/python3.9/site-
packages/django/template/backends/django.py", line 62, in render
return self.template.render(context)
File "/opt/production/lib/python3.9/site-
packages/django/template/base.py", line 175, in render
return self._render(context)
File "/opt/production/lib/python3.9/site-packages/django/test/utils.py",
line 111, in instrumented_test_render
return self.nodelist.render(context)
File "/opt/production/lib/python3.9/site-
packages/django/template/base.py", line 1000, in render
return SafeString("".join([node.render_annotated(context) for node in
self]))
File "/opt/production/lib/python3.9/site-
packages/django/template/base.py", line 1000, in <listcomp>
return SafeString("".join([node.render_annotated(context) for node in
self]))
File "/opt/production/lib/python3.9/site-
packages/django/template/base.py", line 958, in render_annotated
return self.render(context)
File "/opt/production/lib/python3.9/site-
packages/django/template/loader_tags.py", line 157, in render
return compiled_parent._render(context)
File "/opt/production/lib/python3.9/site-packages/django/test/utils.py",
line 111, in instrumented_test_render
return self.nodelist.render(context)
File "/opt/production/lib/python3.9/site-
packages/django/template/base.py", line 1000, in render
return SafeString("".join([node.render_annotated(context) for node in
self]))
File "/opt/production/lib/python3.9/site-
packages/django/template/base.py", line 1000, in <listcomp>
return SafeString("".join([node.render_annotated(context) for node in
self]))
File "/opt/production/lib/python3.9/site-
packages/django/template/base.py", line 958, in render_annotated
return self.render(context)
File "/opt/production/lib/python3.9/site-
packages/django/templatetags/tz.py", line 146, in render
with timezone.override(self.tz.resolve(context)):
File "/opt/production/lib/python3.9/site-
packages/django/utils/timezone.py", line 157, in __enter__
activate(self.timezone)
File "/opt/production/lib/python3.9/site-
packages/django/utils/timezone.py", line 121, in activate
_active.value = zoneinfo.ZoneInfo(timezone)
File "/usr/lib/python3.9/zoneinfo/_common.py", line 24, in load_tzdata
raise ZoneInfoNotFoundError(f"No time zone found with key {key}")
zoneinfo._common.ZoneInfoNotFoundError: 'No time zone found with key '