Version 4.0.21

Released: November 29, 2021

Status: Maintenance


This release consists mostly of fixes and improvements backported from version 4.1.


The transformation cache_hash method was split into two functions to allow sub classes to modify how the cache hash is calculated.

Added asset image cache invalidation. Changing the asset image of an existing decoration will now invalidate the page image cache so that the new image is used.

An a asset duplication issue was fixed.

The asset percentage position calculation was also fixed.


A standalone Celery beat container was added to the default Docker Compose file.

Lock manager

Improvements to the lock manager test cases were merged.


Test models now perform more strict cleanup. The test model app config cache is cleaned after the test unit ends. All test models instances are deleted before deleting the actual test models.


  • Add an explicit default value for MEDIA_URL. Ensures forward compatibility with future login dependency versions.

  • Move meta tags to their own partial template.

  • Add libjpeg and libpng to the dev setup target.


  • None

Upgrade process

Docker Compose

Check the Docker upgrading chapter for the complete upgrade process.

Backward incompatible changes

  • None

Issues closed

  • None