[Sysinfo] Anacron job 'cron.weekly' on line

[Anacron]

/etc/cron.weekly/apt-xapian-index:
Traceback (most recent call last):
  File "/usr/sbin/update-apt-xapian-index", line 720, in <module>
    buildIndex(dbdir, addons, progress)
  File "/usr/sbin/update-apt-xapian-index", line 389, in buildIndex
    for idx, pkg in enumerate(cache):
  File "/usr/lib/python2.6/dist-packages/apt/cache.py", line 161, in __iter__
    yield self[pkgname]
  File "/usr/lib/python2.6/dist-packages/apt/cache.py", line 154, in __getitem__
    pkg = self._weakref[key] = Package(self, self._cache[key])
KeyError: 'moun4py'
run-parts: /etc/cron.weekly/apt-xapian-index exited with return code 1