django.utils.importlib has been removed in django 1.9 [1] and this is
indeed the django release available in both stretch or sid:
python-django:
Installed: 1.9-2
Candidate: 1.9-2
Version table:
*** 1.9-2 500
500 http://http.debian.net/debian sid/main amd64 Packages
100 /var/lib/dpkg/status
1.9-1 500
500 http://http.debian.net/debian stretch/main amd64 Packages
Whereas OpenStack Horizon still depends on Django < 1.9 [2]
Alberto
[1]
https://docs.djangoproject.com/en/1.9/internals/deprecation/#deprecation-removed-in-1-9
[2] https://github.com/openstack/horizon/blob/master/requirements.txt
