Fix: Postgres selection, DBENGINE and migrations (#12299)

src/paperless/checks.py

@@ -7,6 +7,7 @@ from pathlib import Path
 
 from django.conf import settings
 from django.core.checks import Error
+from django.core.checks import Tags
 from django.core.checks import Warning
 from django.core.checks import register
 from django.db import connections
@@ -204,15 +205,16 @@ def audit_log_check(app_configs, **kwargs):
     return result
 
 
-@register()
+@register(Tags.compatibility)
 def check_v3_minimum_upgrade_version(
     app_configs: object,
     **kwargs: object,
 ) -> list[Error]:
-    """Enforce that upgrades to v3 must start from v2.20.9.
+    """
+    Enforce that upgrades to v3 must start from v2.20.10.
 
     v3 squashes all prior migrations into 0001_squashed and 0002_squashed.
-    If a user skips v2.20.9, the data migration in 1075_workflowaction_order
+    If a user skips v2.20.10, the data migration in 1075_workflowaction_order
     never runs and the squash may apply schema changes against an incomplete
     database state.
     """
@@ -239,7 +241,7 @@ def check_v3_minimum_upgrade_version(
         if {"0001_squashed", "0002_squashed"} & applied:
             return []
 
-        # On v2.20.9 exactly — squash will pick up cleanly from here
+        # On v2.20.10 exactly — squash will pick up cleanly from here
         if "1075_workflowaction_order" in applied:
             return []
 
@@ -250,8 +252,8 @@ def check_v3_minimum_upgrade_version(
         Error(
             "Cannot upgrade to Paperless-ngx v3 from this version.",
             hint=(
-                "Upgrading to v3 can only be performed from v2.20.9."
-                "Please upgrade to v2.20.9, run migrations, then upgrade to v3."
+                "Upgrading to v3 can only be performed from v2.20.10."
+                "Please upgrade to v2.20.10, run migrations, then upgrade to v3."
                 "See https://docs.paperless-ngx.com/setup/#upgrading for details."
             ),
             id="paperless.E002",

src/paperless/settings/custom.py

@@ -209,7 +209,6 @@ def parse_db_settings(data_dir: Path) -> dict[str, dict[str, Any]]:
         engine = get_choice_from_env(
             "PAPERLESS_DBENGINE",
             {"sqlite", "postgresql", "mariadb"},
-            default="sqlite",
         )
     except ValueError:
         # MariaDB users already had to set PAPERLESS_DBENGINE, so it was picked up above

src/paperless/tests/test_checks.py

@@ -581,11 +581,11 @@ class TestV3MinimumUpgradeVersionCheck:
     ) -> None:
         """
         GIVEN:
-            - DB is on an old v2 version (pre-v2.20.9)
+            - DB is on an old v2 version (pre-v2.20.10)
         WHEN:
             - The v3 upgrade check runs
         THEN:
-            - The error hint explicitly references v2.20.9 so users know what to do
+            - The error hint explicitly references v2.20.10 so users know what to do
         """
         mocker.patch.dict(
             "paperless.checks.connections",
@@ -593,7 +593,7 @@ class TestV3MinimumUpgradeVersionCheck:
         )
         result = check_v3_minimum_upgrade_version(None)
         assert len(result) == 1
-        assert "v2.20.9" in result[0].hint
+        assert "v2.20.10" in result[0].hint
 
     def test_db_error_is_swallowed(self, mocker: MockerFixture) -> None:
         """