new_contents: import os
  import pathlib
  import subprocess
  
  from django.conf import settings
  from django.test import TestCase
  
  
  class MakeMessagesCommandRunTestCase(TestCase):
      """
      Sanity check to make sure makemessages runs to completion.
      """
  
      def test_command_succeeds_without_postgres(self):
          """
          Test that we can run makemessages when postgres is not activated.
          """
          repo_root = pathlib.Path(settings.BASE_DIR).parent
          cmd = ["make", "makemessages"]
          env = os.environ.copy()
          # We fake postgres not being available, by setting the wrong IP address.
          # hopefully postgres isn't running at 127.0.0.2!
          env.update({"DATA_DB_HOST": "127.0.0.2"})
          subprocess.check_output(
              cmd,
              env=env,
              cwd=str(repo_root)
          )
  
subject: Write test to confirm that makemessages works without needing postgres