Docs for what goes in DATABASE_ENGINE is wrong

[HM]

According to settings.txt,

In the Django development version, you can use a database backend that doesn’t 
ship with Django by setting DATABASE_ENGINE to a fully-qualified path (i.e. 
mypackage.backends.whatever). Writing a whole new database backend from
scratch is left as an exercise to the reader; see the other backends for examples.

However, attempting to do this leads to:

  ..
  File "/usr/lib/python2.5/site-packages/django/db/__init__.py", line 32, in <module>
    (settings.DATABASE_ENGINE, ", ".join(map(repr, available_backends)))
django.core.exceptions.ImproperlyConfigured: 'extra.backends.psycopg2_sequencesafe' isn't 
an available database backend. Available options are: 'ado_mssql', 'dummy', 'mysql', 
'mysql_old', 'oracle', 'postgresql', 'postgresql_psycopg2', 'sqlite3'

as of trunk version 7167. See also ticket #1946

[Ramiro Morales]

Just tried with a bogus custom backend and I'm not getting this error (I'm getting another one but that's because it is composed of 0 byte-sized .py files, but it has alerady passed the backend importability validation point). Are you sure you are correctly adding your new backend's module path to the Python path? Are you creating the base module beneath it?.

As the docs say, see the other backend for examples, and may I add: "Use the source Luke": ​http://code.djangoproject.com/browser/django/trunk/django/db/__init__.py#L23