Proposed fix for handling duplicates not as a hard error, but are merely a stop processing

src/documents/consumer.py

@@ -40,6 +40,7 @@ from documents.plugins.base import AlwaysRunPluginMixin
 from documents.plugins.base import ConsumeTaskPlugin
 from documents.plugins.base import NoCleanupPluginMixin
 from documents.plugins.base import NoSetupPluginMixin
+from documents.plugins.base import StopConsumeTaskError
 from documents.plugins.date_parsing import get_date_parser
 from documents.plugins.helpers import ProgressManager
 from documents.plugins.helpers import ProgressStatusOptions
@@ -960,10 +961,14 @@ class ConsumerPreflightPlugin(
                     )
                     failure_msg += " Note: existing document is in the trash."
 
-                self._fail(
+                self._send_progress(
+                    100,
+                    100,
+                    ProgressStatusOptions.FAILED,
                     status_msg,
-                    failure_msg,
                 )
+                self.log.error(failure_msg)
+                raise StopConsumeTaskError(failure_msg)
 
     def pre_check_directories(self) -> None:
         """

src/documents/tests/test_consumer.py

@@ -29,6 +29,7 @@ from documents.models import StoragePath
 from documents.models import Tag
 from documents.parsers import DocumentParser
 from documents.parsers import ParseError
+from documents.plugins.base import StopConsumeTaskError
 from documents.plugins.helpers import ProgressStatusOptions
 from documents.tasks import sanity_check
 from documents.tests.utils import DirectoriesMixin
@@ -952,11 +953,11 @@ class TestConsumer(
         self.assertIsFile(dst)
 
         expected_message = (
-            f"{dst.name}: Not consuming {dst.name}: "
+            f"Not consuming {dst.name}: "
             f"It is a duplicate of {document.title} (#{document.pk})"
         )
 
-        with self.assertRaisesMessage(ConsumerError, expected_message):
+        with self.assertRaisesMessage(StopConsumeTaskError, expected_message):
             with self.get_consumer(dst) as consumer:
                 consumer.run()
 
@@ -978,12 +979,12 @@ class TestConsumer(
         self.assertIsFile(dst)
 
         expected_message = (
-            f"{dst.name}: Not consuming {dst.name}: "
+            f"Not consuming {dst.name}: "
             f"It is a duplicate of {document.title} (#{document.pk})"
             f" Note: existing document is in the trash."
         )
 
-        with self.assertRaisesMessage(ConsumerError, expected_message):
+        with self.assertRaisesMessage(StopConsumeTaskError, expected_message):
             with self.get_consumer(dst) as consumer:
                 consumer.run()