If I quit out of preupgrade when it complains /boot is too small, make more space, restart and opt to continue the existing upgrade, it crashes with the error

Traceback (most recent call last):
  File "/usr/share/preupgrade/preupgrade-gtk.py", line 773, in <module>
    widgets = PreUpgradeGtk()
  File "/usr/share/preupgrade/preupgrade-gtk.py", line 376, in __init__
    self._do_main()
  File "/usr/share/preupgrade/preupgrade-gtk.py", line 259, in _do_main
    self.main_preupgrade()
  File "/usr/share/preupgrade/preupgrade-gtk.py", line 436, in main_preupgrade
    download_progressbar=self.dnlProgress)
  File "/usr/lib/python2.6/site-packages/preupgrade/__init__.py", line 130, in setup
    self.complete_repo_setup()
  File "/usr/lib/python2.6/site-packages/preupgrade/__init__.py", line 328, in complete_repo_setup
    repo._grabfunc.opts.user_agent = __user_agent__
AttributeError: 'NoneType' object has no attribute 'opts'