Catch recursive tree error for part / variant relationship

InvenTree/part/models.py

@@ -27,6 +27,7 @@ from markdownx.models import MarkdownxField
 from django_cleanup import cleanup
 
 from mptt.models import TreeForeignKey, MPTTModel
+from mptt.exceptions import InvalidMove
 from mptt.managers import TreeManager
 
 from stdimage.models import StdImageField
@@ -426,7 +427,12 @@ class Part(MPTTModel):
 
         self.full_clean()
 
-        super().save(*args, **kwargs)
+        try:
+            super().save(*args, **kwargs)
+        except InvalidMove:
+            raise ValidationError({
+                'variant_of': _('Invalid choice for parent part'),
+            })
 
         if add_category_templates:
             # Get part category