Pre-compile fixtures for unit tests.
Django's fixture support is extraordinarily inefficient. For every

single unit test, it does the following:

Recalculates the list of possible fixture directories
Locates each fixture file within those directories
Tries to figure out how to deserialize them
Deserializes them
Saves them

That's done per-test. Most of those operations are things that could be

easily cached, including the deserialized fixture content.
Our TestCase rewrites fixture loading to do just this. When we see a new

fixture, we precompile it, getting the list of objects and storing it.

We then use that precompiled version whenever the fixture is requested

for future tests.
This saves 10 seconds on the test suite.

Ran 746 tests in 80.604s