Release note for non-fts sqlite support

CHANGELOG.txt

@@ -40,6 +40,7 @@ Changelog
  * Fix: Ensure that bulk publish actions pick up the latest draft revision (Matt Westcott)
  * Fix: Ensure the `checkbox_aria_label` is used correctly in the Bulk Actions checkboxes (Vu Pham)
  * Fix: Prevent error on MySQL search backend when searching three or more terms (Aldán Creo)
+ * Fix: Allow wagtail.search app migrations to complete on versions of SQLite without full-text search support (Matt Westcott)
 
 
 2.15.1 (11.11.2021)

docs/releases/2.15.2.rst

@@ -18,3 +18,23 @@ Bug fixes
  * Ensure that bulk publish actions pick up the latest draft revision (Matt Westcott)
  * Ensure the ``checkbox_aria_label`` is used correctly in the Bulk Actions checkboxes (Vu Pham)
  * Prevent error on MySQL search backend when searching three or more terms (Aldán Creo)
+ * Allow wagtail.search app migrations to complete on versions of SQLite without full-text search support (Matt Westcott)
+
+
+Upgrade considerations
+======================
+
+Support for SQLite without full-text search support
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This release restores the ability to run Wagtail against installations of SQLite that do not include the ``fts5`` extension for full-text search support. On these installations, the fallback search backend (without support for full-text queries) will be used, and the database table for storing indexed content will not be created.
+
+If SQLite is subsequently upgraded to a version with ``fts5`` support, existing databases will still be missing this table, and full-text search will continue to be unavailable until it is created. To correct this, first make a backup copy of the database (since rolling back the migration could potentially reverse other schema changes), then run:
+
+.. code-block:: console
+
+  ./manage.py migrate wagtailsearch 0005
+  ./manage.py migrate
+  ./manage.py update_index
+
+Additionally, since the database search backend now needs to run a query on initialisation to check for the presence of this table, calling ``wagtail.search.backends.get_search_backend`` during application startup may now fail with a "Models aren't loaded yet" error. Code that does this should be updated to only call ``get_search_backend`` at the point when a search query is to be performed.