Add a note that `TEMPLATE_DEBUG` must be enabled.

[charettes]

I had to read the source to figure out it was required. Fixing the TODO would also be nice.

[nedbat]

Even better, I'd like to add an automated warning message if TEMPLATE_DEBUG is not set.

[audreyfeldroy]

Just fyi, as of Django 1.8, TEMPLATE_DEBUG is deprecated: https://docs.djangoproject.com/en/1.8/ref/settings/#template-debug

[charettes]

It has been replaced by the 'debug' option in the OPTIONS of a DjangoTemplates backend.

[nedbat]

This is handled in 99ba553

[charettes]

Thanks Ned!

[jonashaag]

Will you cut a a release with this fix soon? I spent almost an hour debugging this.

[nedbat]

Version 1.2 is on PyPI now, with this fix. Sorry for the delay :)

[jonashaag]

Thank you!