Ignore unpaper warning message when checking version

Fixes #1409

src/ocrmypdf/_exec/unpaper.py

@@ -48,7 +48,7 @@ def __init__(
 
 
 def version() -> Version:
-    return Version(get_version('unpaper'))
+    return Version(get_version('unpaper', regex=r'(?m).*(\d+(\.\d+)(\.\d+)?)'))
 
 
 @contextmanager

tests/test_unpaper.py

@@ -5,7 +5,7 @@
 
 import logging
 from os import fspath
-from unittest.mock import patch
+from unittest.mock import Mock, patch
 
 import pytest
 from packaging.version import Version
@@ -48,6 +48,19 @@ def test_old_unpaper(resources, no_outpdf):
         mock.assert_called()
 
 
+def test_unpaper_version_chatter(resources, no_outpdf):
+    input_ = fspath(resources / "c02-22.pdf")
+    output = fspath(no_outpdf)
+
+    _parser, options, pm = get_parser_options_plugins(["--clean", input_, output])
+    with patch("ocrmypdf.subprocess.run") as mock:
+        mock.return_value = Mock(stdout='Warning: using insecure memory!\n7.0.0\n')
+
+        with pytest.raises(MissingDependencyError):
+            check_options(options, pm)
+        mock.assert_called()
+
+
 @needs_unpaper
 def test_clean(resources, outpdf):
     check_ocrmypdf(