id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
27544	F() Expressions updating dates in .update() field fails on SQLite	Gary Graham	Andrew Nester	"Upon upgrading from 1.8 -> 1.10, I noticed that some code I had written now threw an error.  Specifically, attempting to update datetime field's via F expression.

Branch with test showing regression -> https://github.com/tadgh/django/commit/c31133261c68b10525b8e3b34e6895a0c6ece4d0

Bisected to ed83881e648771d22658f21b939f66e75c499864: Fixed #23820 -- Supported per-database time zone. 

Stacktrace from failure:
{{{
======================================================================
ERROR: test_F_expression_fails (timezones.test_regression.ProveRegression)
----------------------------------------------------------------------
Traceback (most recent call last):
  File ""/home/tadgh/Projects/django/tests/timezones/test_regression.py"", line 22, in test_F_expression_fails
    self.timestamp.refresh_from_db()
  File ""/home/tadgh/Projects/django/django/db/models/base.py"", line 585, in refresh_from_db
    db_instance = db_instance_qs.get()
  File ""/home/tadgh/Projects/django/django/db/models/query.py"", line 381, in get
    num = len(clone)
  File ""/home/tadgh/Projects/django/django/db/models/query.py"", line 240, in __len__
    self._fetch_all()
  File ""/home/tadgh/Projects/django/django/db/models/query.py"", line 1061, in _fetch_all
    self._result_cache = list(self.iterator())
  File ""/home/tadgh/Projects/django/django/db/models/query.py"", line 68, in __iter__
    for row in compiler.results_iter(results):
  File ""/home/tadgh/Projects/django/django/db/models/sql/compiler.py"", line 806, in results_iter
    row = self.apply_converters(row, converters)
  File ""/home/tadgh/Projects/django/django/db/models/sql/compiler.py"", line 790, in apply_converters
    value = converter(value, expression, self.connection, self.query.context)
  File ""/home/tadgh/Projects/django/django/db/backends/sqlite3/operations.py"", line 159, in convert_datetimefield_value
    value = timezone.make_aware(value, self.connection.timezone)
  File ""/home/tadgh/Projects/django/django/utils/timezone.py"", line 364, in make_aware
    return timezone.localize(value, is_dst=is_dst)
  File ""/home/tadgh/.venvs/django_env/lib/python3.4/site-packages/pytz/__init__.py"", line 227, in localize
    raise ValueError('Not naive datetime (tzinfo is already set)')
ValueError: Not naive datetime (tzinfo is already set)
}}}"	Bug	closed	Database layer (models, ORM)	1.10	Normal	fixed	F()		Accepted	1	0	0	0	0	0