manage.py command "ping_google" requires django.contrib.sites to work but it's not documented

[GOTO Hayato]

I tried to use ping_google in my Django site with the following command after adding django.contrib.sitemaps to settings.INSTALLED_APPS.

python manage.py ping_google

Then, I got an error like:

django.core.exceptions.ImproperlyConfigured: ping_google requires django.contrib.sites, which isn't installed.

Seeing the related code, it seems that the command requires django.contrib.sites to be installed to work.

def _get_sitemap_full_url(sitemap_url):
    if not django_apps.is_installed('django.contrib.sites'):
        raise ImproperlyConfigured("ping_google requires django.contrib.sites, which isn't installed.")

​https://docs.djangoproject.com/en/2.0/_modules/django/contrib/sitemaps/

I believe it's better to add some notes for this in the documentation.

​https://docs.djangoproject.com/en/2.0/ref/contrib/sitemaps/#pinging-google

(This is my first challenge to file an issue here. I'm sorry if I'm missing or misunderstanding anything crucial.)

[Tim Graham]

Step 3 of the ​sitemaps installation is "Make sure you’ve installed the sites framework." so I think another mention of it would be redundant and the error message seems good enough?

[GOTO Hayato]

Tim, thank you for your reply. You're right. It was my fault and the current documentation and error message are enough. Thanks for taking a time.