Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 961, in simulate trans.unauthenticated = self._simulate_helper(trans) File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 1085, in _simulate_helper return depends, self._cache.required_download, \ File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 226, in required_download pm.get_archives(fetcher, self._list, self._records) SystemError: E:I wasn't able to locate file for the avida-base package. This might mean you need to manually fix this package.