Fix: ghostscript rendering error doesnt trigger frontend failure message (#4092)

* Raise ParseError from gs rendering error

* catch all parser errors as generic exception

* Differentiate generic vs parse errors during consumption

src/paperless_tesseract/parsers.py

@@ -340,7 +340,10 @@ class RasterisedDocumentParser(DocumentParser):
                     "Ghostscript PDF/A rendering failed, consider setting "
                     "PAPERLESS_OCR_USER_ARGS: '{\"continue_on_soft_render_error\": true}'",  # noqa: E501
                 )
-            raise e
+
+            raise ParseError(
+                f"SubprocessOutputError: {e!s}. See logs for more information.",
+            ) from e
         except (NoTextFoundException, InputFileError) as e:
             self.log.warning(
                 f"Encountered an error while running OCR: {e!s}. "

src/paperless_tesseract/tests/test_parser.py

@@ -8,6 +8,7 @@ from unittest import mock
 
 from django.test import TestCase
 from django.test import override_settings
+from ocrmypdf import SubprocessOutputError
 
 from documents.parsers import ParseError
 from documents.parsers import run_convert
@@ -827,6 +828,18 @@ class TestParser(DirectoriesMixin, FileSystemAssertsMixin, TestCase):
         # Copied from the PDF to here.  Don't even look at it
         self.assertIn("ةﯾﻠﺧﺎدﻻ ةرازو", parser.get_text())
 
+    @mock.patch("ocrmypdf.ocr")
+    def test_gs_rendering_error(self, m):
+        m.side_effect = SubprocessOutputError("Ghostscript PDF/A rendering failed")
+        parser = RasterisedDocumentParser(None)
+
+        self.assertRaises(
+            ParseError,
+            parser.parse,
+            os.path.join(self.SAMPLE_FILES, "simple-digital.pdf"),
+            "application/pdf",
+        )
+
 
 class TestParserFileTypes(DirectoriesMixin, FileSystemAssertsMixin, TestCase):
     SAMPLE_FILES = os.path.join(os.path.dirname(__file__), "samples")