Ludibrio hangs test execution

I have a Django project with some tests, including Geocoder mock that starts like this:

with Stub(proxy=Geocoder) as Geocoder:
    from pygeocoder import Geocoder

The from import will cause the text execution to hang (100% CPU usage, kill needed) when I add 'djcelery' to installed apps. (and maybe other applications). Without it the tests work normally.
