Django Haystack Rebuild Index

I was reading the 'Getting Started' guide of Haystack and tried to implement Whoosh backend for my website with Haystack. I was successful in setting up the whole project and I can also see the search box o开发者_如何学Gon my search.html template. I am unable to build the index though.

When I type ./manage.py rebuild_index, I get the error:

Unknown command: rebuild_index

I know this is a trivial issue. I am unable to understand how the manage.py file can ever understand commands that were not originally a part of it.

Do you have haystack in your INSTALLED_APPS?

manage.py learns new commands by importing the settings.py file and loading modules from your INSTALLED_APPS variable.