Problems with contenttypes when loading a fixture in Django

manage.py dumpdata --natural will use a more durable representation of foreign keys. In django they are called "natural keys". For example:

• Permission.codename is used in favour of Permission.id
• User.username is used in favour of User.id

Read more: natural keys section in "serializing django objects"

Some other useful arguments for dumpdata:

• --indent=4 make it human readable.
• -e sessions exclude session data
• -e admin exclude history of admin actions on admin site
• -e contenttypes -e auth.Permission exclude objects which are recreated automatically from schema every time during syncdb. Only use it together with --natural or else you might end up with badly aligned id numbers.

The answers here all old... As of 2017, the best answer is:

manage.py dumpdata --natural-foreign --natural-primary -e contenttypes -e auth.Permission --indent 4

Yes, this is really irritating. For a while I worked around it by doing a "manage.py reset" on the contenttypes app prior to loading the fixture (to get rid of the automatically-generated contenttypes data that differed from the dumped version). That worked, but eventually I got sick of the hassles and abandoned fixtures entirely in favor of straight SQL dumps (of course, then you lose DB portability).

update - the best answer is to use the --natural flag to dumpdata, as noted in an answer below. That flag did not exist yet when I wrote this answer.