Debugging python with C++ extensions

[Karl G. Merkley]

I am looking using python as a framework for some C++ components.
However, I am concerned about debugging across the python/C++ interface.
How do people currently debug python with C++ extensions.  Every C++
component will have it's own unit test; however, it seems inevitable that
there will be times when it would be helpful to step from the python
code into the C++ component.

Comments?

   Thanks,
      Karl