data: raise a CommandError if import-site fails when roles are missing (#35289)

combo/data/management/commands/import_site.py

@@ -17,7 +17,7 @@
 import json
 import sys
 
-from django.core.management.base import BaseCommand
+from django.core.management.base import BaseCommand, CommandError
 from django.utils.encoding import force_text
 
 from combo.data.utils import import_site, MissingGroups
@@ -45,4 +45,4 @@ class Command(BaseCommand):
                         if_empty=options['if_empty'],
                         clean=options['clean'])
         except MissingGroups as e:
-            sys.stderr.write(force_text(e) + '\n')
+            raise CommandError(e)

tests/test_import_export.py

@@ -10,6 +10,7 @@ import pytest
 from django.contrib.auth.models import Group
 from django.core.files import File
 from django.core.management import call_command
+from django.core.management.base import CommandError
 from django.utils.encoding import force_bytes, force_text
 from django.utils.six import BytesIO, StringIO
 
@@ -161,6 +162,13 @@ def test_group_restrictions_import_export(app, some_data):
 
     assert excinfo.value.names == ['A Group']
 
+    with pytest.raises(CommandError, match='Missing groups: A Group'):
+        with tempfile.NamedTemporaryFile() as f:
+            f.write(force_bytes(output))
+            f.flush()
+            call_command('import_site', f.name, clean=True)
+    assert Page.objects.count() == 0
+
     group = Group(name='A Group')
     group.save()