nosetests --pdb let\'s me halt upon error or failure, but this is too late for my needs. Stepping through code during execution helps me debug where the problem is.
nosetests --pdb
You can add
import pdb; pdb.set_trace()
anywhere in your source that you want to stop in the debugger.
Make sure you pass -s to nose so that it does not capture stdout.
-s
stdout