string_concat is removed from django as of 2.1

[Corey Bryant]

I just tripped over this in Ubuntu development of Eoan (Train) where we are moving from python-django 1.11.22 to python-django 2.2.3.

The traceback ends with:

File "/usr/lib/python3/dist-packages/openstack_dashboard/dashboards/project/instances/tables.py", line 27, in <module>
  from django.utils.translation import string_concat
ImportError: cannot import name 'string_concat' from 'django.utils.translation' (/usr/lib/python3/dist-packages/django/utils/translation/__init__.py)

https://github.com/django/django/blob/master/docs/releases/2.1.txt states that "django.utils.translation.string_concat() is removed."

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/671045

[Launchpad Janitor (janitor)]

This bug was fixed in the package horizon - 3:16.0.0~b1~git2019061445.2cb84ade8-0ubuntu2

---------------
horizon (3:16.0.0~b1~git2019061445.2cb84ade8-0ubuntu2) eoan; urgency=medium

  * d/p/switch-from-django-string_compat-to-format_lazy.patch: Cherry-picked
    from https://review.opendev.org/#/c/671045 to enable use of horizon with
    python-django >= 2.1 (LP: #1836671).

 -- Corey Bryant <email address hidden> Tue, 16 Jul 2019 10:03:17 -0400

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/671045
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=6f4742457fae755e465315f17f39c3977c833d0e
Submitter: Zuul
Branch: master

commit 6f4742457fae755e465315f17f39c3977c833d0e
Author: Corey Bryant <email address hidden>
Date: Tue Jul 16 09:56:48 2019 -0400

    Switch from django string_concat to format_lazy

    string_concat was removed in django 2.1 when it reached the end
    of it's deprecation cycle. It was removed because the same behavior
    can be achieved with format_lazy.

    For more details see:
    https://docs.djangoproject.com/en/2.2/releases/2.1/

    Change-Id: I5e1c9bdfa1d0e049e0516198abbdb76be1667216
    Closes-Bug: #1836671
    Partial-Bug: #1789046

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/horizon 16.0.0.0b2 development milestone.