ipython/ipython — pull request #3511 by punchagan (2013-07-02 08:14:52+00:00)
Title: Get Tracer working after ipapi.get replaced with get_ipython

Commit 790f731 replaced `ipapi.get` with a `get_ipython` function,
that changed the API slightly, returning None when no InteractiveShell
instance has been registered.