Contains process lock related improvements and export exception handling added in #3197506: Test Drush integration
Fixes to underneath form for login page
Many D8 compatibility fixes and D9 support Improvements to styling
Includes a workaround for a Drupal packaging issue which makes it impossible to install the 8.x-3.1 release on Drupal 8.9
Details: Package information is malformed by Drupal.org packagist #3197662