[Django] #34948: USE_TZ=False causes failure in AdminEmailHandler during DST "fall back"

[Django]

#34948: USE_TZ=False causes failure in AdminEmailHandler during DST "fall back"
-----------------------------------------+------------------------
Reporter: Thomas Smith | Owner: nobody
Type: Bug | Status: new
Component: Uncategorized | Version: 3.2
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 |
-----------------------------------------+------------------------
In the AdminEmailHandler, it renders the current time:
(the first one).
{{{
Server time: {{server_time|date:"r"}}
}}}

Over the weekend, in our server, which has USE_TZ=False, that resulted in
an AmbiguousTimeError ''inside logger.exception(...):''

{{{
try:
do_some_stuff_that_might_fail()
except Exception:
logger.exception()
}}}

So our attempt to quickly move on from a failure in
`do_some_stuff_that_might_fail()` did not work and it crashed the
application (since it was called from module-level code).

This occurred at 1:42 AM EDT, and of course stopped being a problem after
2:00 AM EST.

Desired behavior: render the admin email with an ambiguous time if needed,
but don't throw an exception from inside the exception handler

Backtrace:

{{{
File "our_app.py", line 298, in do_things_at_startup.py
logger.exception(e)
File "logging/__init__.py", line 1479, in exception
Convenience method for logging an ERROR with exception information.
File "logging/__init__.py", line 1481, in exception
self.error(msg, *args, exc_info=exc_info, **kwargs)
File "logging/__init__.py", line 1467, in error
Log 'msg % args' with severity 'ERROR'.
File "logging/__init__.py", line 1475, in error
self._log(ERROR, msg, args, **kwargs)
File "logging/__init__.py", line 1589, in _log
self.handle(record)
File "logging/__init__.py", line 1599, in handle
self.callHandlers(record)
File "logging/__init__.py", line 1661, in callHandlers
hdlr.handle(record)
File "logging/__init__.py", line 952, in handle
self.emit(record)
File "django/utils/log.py", line 120, in emit
message = "%s\n\n%s" % (self.format(no_exc_record),
reporter.get_traceback_text())
File "django/views/debug.py", line 353, in get_traceback_text
return t.render(c)
File "django/template/base.py", line 170, in render
return self._render(context)
File "django/template/base.py", line 162, in _render
return self.nodelist.render(context)
File "django/template/base.py", line 938, in render
bit = node.render_annotated(context)
File "django/template/base.py", line 905, in render_annotated
return self.render(context)
File "django/template/base.py", line 988, in render
output = self.filter_expression.resolve(context)
File "django/template/base.py", line 698, in resolve
new_obj = func(obj, *arg_vals)
File "django/template/defaultfilters.py", line 729, in date
return formats.date_format(value, arg)
File "django/utils/formats.py", line 152, in date_format
return dateformat.format(value, get_format(format or 'DATE_FORMAT',
use_l10n=use_l10n))
File "django/utils/dateformat.py", line 327, in format
return df.format(format_string)
File "django/utils/dateformat.py", line 42, in format
pieces.append(str(getattr(self, piece)()))
File "django/utils/dateformat.py", line 274, in r
dt = make_aware(self.data, timezone=self.timezone)
File "django/utils/timezone.py", line 242, in make_aware
return timezone.localize(value, is_dst=is_dst)
File "pytz/tzinfo.py", line 366, in localize
raise AmbiguousTimeError(dt)
}}}

--
Ticket URL: <https://code.djangoproject.com/ticket/34948>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.

[Django]

#34948: USE_TZ=False causes failure in AdminEmailHandler during DST "fall back"

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

Reporter: Thomas Smith | Owner: nobody

Type: Bug | Status: closed
Component: Utilities | Version: 3.2
Severity: Normal | Resolution: invalid

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 Mariusz Felisiak):

* status: new => closed
* resolution: => invalid
* component: Uncategorized => Utilities

Comment:

Thanks for the report, however, Django 3.2 is the extended support so it
doesn't receive bugfixes anymore (expect security patches) and Django 5.0+
no longer uses `pytz`. Finally, it's
[https://docs.djangoproject.com/en/4.2/ref/utils/#django.utils.timezone.make_aware
documented] that `pytz.AmbiguousTimeError` may be raised during a DST
transition in Django versions < 5.0.

--
Ticket URL: <https://code.djangoproject.com/ticket/34948#comment:1>