Addressed a crash on Django 4.1+ for makemigrations --merge.

Thanks @AvivAvitan for the report.

syzygy/management/commands/makemigrations.py

@@ -1,5 +1,3 @@
-from functools import partial
-
 from django.core.management.commands import makemigrations  # type: ignore
 
 from syzygy.autodetector import MigrationAutodetector
@@ -23,9 +21,13 @@ def handle(self, *args, disable_syzygy, **options):
         # Monkey-patch makemigrations.MigrationAutodetector since the command
         # doesn't allow it to be overridden in any other way.
         MigrationAutodetector_ = makemigrations.MigrationAutodetector
-        makemigrations.MigrationAutodetector = partial(
-            MigrationAutodetector, style=self.style
-        )
+        style = self.style
+
+        class StyledMigrationAutodetector(MigrationAutodetector):
+            def __init__(self, *args, **kwargs):
+                super().__init__(*args, **kwargs, style=style)
+
+        makemigrations.MigrationAutodetector = StyledMigrationAutodetector
         try:
             super().handle(*args, **options)
         finally:

tests/test_commands.py

@@ -159,3 +159,20 @@ def test_null_field_removal(self):
         self.assertIn("- Set database DEFAULT of field bar on foo", output)
         self.assertIn("null_field_removal/0003_remove_foo_bar.py", output)
         self.assertIn("- Remove field bar from foo", output)
+
+    @override_settings(
+        MIGRATION_MODULES={"tests": "tests.test_migrations.merge_conflict"}
+    )
+    def test_merge_conflict(self):
+        stdout = StringIO()
+        call_command(
+            "makemigrations",
+            "tests",
+            merge=True,
+            interactive=False,
+            no_color=True,
+            dry_run=True,
+            stdout=stdout,
+        )
+        self.assertIn("0002_first", stdout.getvalue())
+        self.assertIn("0002_second", stdout.getvalue())

tests/test_migrations/merge_conflict/0001_initial.py

@@ -0,0 +1,5 @@
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    pass

tests/test_migrations/merge_conflict/0002_first.py

@@ -0,0 +1,5 @@
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    dependencies = [("tests", "0001_initial")]

tests/test_migrations/merge_conflict/0002_second.py

@@ -0,0 +1,5 @@
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    dependencies = [("tests", "0001_initial")]