'manage.py validate reports an error on a non-existent app in INSTALLED_APPS'

def test_nonexistent_app(self):

    self.write_settings('settings.py', apps=['admin_scriptz.broken_app'], sdict={'USE_I18N': False})
    args = ['validate']
    (out, err) = self.run_manage(args)
    self.assertNoOutput(out)
    self.assertOutput(err, 'No    module    named    admin_scriptz')
