-parser.add_argument('distro', choices=['bionic-dev','jessie-dev','precise-dev','stretch-dev','trusty-dev','wheezy-dev','xenial-dev','buster-dev'],
- help='distro to do the clean up')
+parser.add_argument('distro',
+ type=distro,
+ help='distro to process, must be a dev repository, e.g. buster-dev')