Description of problem:

anaconda fails during upgrade from FC4 to FC6 (see stack trace)

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


How reproducible:

every time - I was not able to upgrade at all, had to do a fresh install


Steps to Reproduce:
1. Choose upgrade existing FC installation
2. 
3.
  
Actual results:

raceback (most recent call first):
  File "/usr/lib/python2.4/site-packages/yum/packages.py", line 612, in tagByName
    raise Errors.MiscError, "Unknown header tag %s" % tag
  File "/usr/lib/python2.4/site-packages/yum/packages.py", line 629, in returnSimple
    return self.tagByName(thing)
  File "/usr/lib/anaconda/sortedtransaction.py", line 17, in __getMedia
    uri = po.returnSimple('basepath')
  File "/usr/lib/anaconda/sortedtransaction.py", line 42, in add
    id = self.__getMedia(txmember.po)
  File "/usr/lib/python2.4/site-packages/yum/transactioninfo.py", line 255, in
addErase
    self.add(txmbr)
  File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 1950, in remove
    txmbr = self.tsInfo.addErase(po)
  File "/usr/lib/anaconda/yuminstall.py", line 959, in doPostSelection
    self.ayum.remove(name=pkgname, arch=pkgarch)
  File "/usr/lib/anaconda/backend.py", line 154, in doPostSelection
    return anaconda.backend.doPostSelection(anaconda)
  File "/usr/lib/anaconda/dispatch.py", line 200, in moveStep
    rc = stepFunc(self.anaconda)
  File "/usr/lib/anaconda/dispatch.py", line 123, in gotoNext
    self.moveStep()
  File "/usr/lib/anaconda/gui.py", line 919, in nextClicked
    self.anaconda.dispatch.gotoNext()
MiscError: Unknown header tag basepath

Local variables in innermost frame:
self: system-config-mouse - 1.2.11-1.noarch
tag: basepath
e: 'unknown header tag'

see full stack trace as attachment

Expected results:

anaconda not exiting

Additional info: