Description of problem:

Pup backtraced on a recent update.

Version-Release number of selected component (if applicable):

[jwboyer@yoda ~]$ rpm -q pup
pup-0.1.6-1

How reproducible:

Not sure.

Steps to Reproduce:
1. Start pup
2. Accept updates
3. Marvel at the lovely python backtrace
  
Actual results:

[root@yoda ~]# pup
Traceback (most recent call last):
  File "/usr/share/pup/pup/pup.py", line 536, in _apply
    self._checkDeps()
  File "/usr/share/pup/pup/pup.py", line 778, in _checkDeps
    _("Unable to resolve dependencies for some "
  File "/usr/share/pup/pup/pup.py", line 131, in __init__
    i.set_from_stock(self._get_stock_from_type(type), 6)
AttributeError: 'NoneType' object has no attribute 'set_from_stock'

> /usr/share/pup/pup/pup.py(131)__init__()
-> i.set_from_stock(self._get_stock_from_type(type), 6)
(Pdb)                
                                      
Expected results:

Update completes :)

Additional info:

I still have pup sitting at the python debugger propmpt.  I know very little
about using pdb, but I intend to leave it there in case there is something that
will help.