Comment 1 for bug 1737442

Various temporary problems with package lists can make u-u crash (typically in --download-only mode), but those can be handled printing an error and exiting.

Traceback (most recent call last):
  File "/usr/bin/unattended-upgrade", line 1706, in <module>
    main(options)
  File "/usr/bin/unattended-upgrade", line 1394, in main
    allowed_origins=allowed_origins)
  File "/usr/bin/unattended-upgrade", line 119, in __init__
    apt.Cache.__init__(self, rootdir=rootdir)
  File "/usr/lib/python3/dist-packages/apt/cache.py", line 113, in __init__
    self.open(progress)
  File "/usr/lib/python3/dist-packages/apt/cache.py", line 164, in open
    self._cache = apt_pkg.Cache(progress)
apt_pkg.Error: E:Encountered a section with no Package: header, E:Problem with MergeList /var/lib/apt/lists/cn.archive.ubuntu.com_ubuntu_dists_artful_universe_i18n_Translation-en, E:The package lists or status file could not be parsed or opened.