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
28223	Form not always picklable due to template renderer	Claude Paroz	Hwayoung Cha	"I'm confronted with a random pickling issue with some forms in Django 1.11.
The error is :  `PicklingError: Can't pickle <type 'function'>: attribute lookup __builtin__.function failed`

I tracked the pickling error to the Form.renderer.engine.engine.template_libraries dict.

I can more or less reproduce (different error message, but hopefully same cause) with:
{{{
from django.forms.renderers import get_default_renderer
import pickle
renderer = get_default_renderer()
renderer.engine
pickle.dumps(renderer)

PicklingError: Can't pickle <function add_preserved_filters at 0x7f2468bfc620>: it's not the same object as django.contrib.admin.templatetags.admin_urls.add_preserved_filters
}}}"	Bug	assigned	Forms	1.11	Normal			Torsten Bronger Martin H. Matti Haavikko	Accepted	0	0	0	0	0	0