In your wsgi wrapper you can do something like:

from roundup.cgi.wsgi_handler import RequestDispatcher

class MyRequestDispatcher(RequestDispatcher):
    def __init__(self, home):
        RequestDispatcher.__init__(self, home)

    @contextmanager
    def get_tracker(self):
        tracker = ...
        yield tracker

tracker_home = '/path/to/tracker/home'
app = MyRequestDispatcher(tracker_home)