I've been able to work around this problem by adding /usr/share/python- support/python-urlgrabber to my PYTHONPATH before running yum, though presumably there's a better fix to be had.
-- Unable to run Yum in Edgy https://launchpad.net/bugs/71773 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
