Django 3.1.4 release notes

Django 3.1.4 fixes several bugs in 3.1.3.

• Fixed setting the HTTP header in AsyncRequestFactory (#32162).
• Fixed crash of key transforms for on PostgreSQL when using on a Subquery() annotation (#32182).
• Fixed a regression in Django 3.1 that caused a crash of auto-reloader for certain invocations of runserver on Windows with Python 3.7 and below ().
• Fixed a regression in Django 3.1 that caused suppressing connection errors when JSONField is used on SQLite ().
• Fixed a crash on SQLite, when QuerySet.values()/values_list() contained key transforms for returning non-string primitive values ().