Bug#965050: python3-flask-babel: flask_babel broken after recent werkzeug update

[Raja R Harinath <harinath@hurrynot.org>]

Package: python3-flask-babel
Version: 0.11.2-3
Severity: normal
Tags: upstream
X-Debbugs-Cc: harinath@hurrynot.org

Dear Maintainer,

I use 'fava' which appears to use 'flask_babel'.  Recently, 'fava' started
crashing with the following backtrace:

--8<--
Traceback (most recent call last):
  File "/usr/bin/fava", line 11, in <module>
    load_entry_point('fava==1.14', 'console_scripts', 'fava')()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 490, in
load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2859,
in load_entry_point
    return ep.load()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2450,
in load
    return self.resolve()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2456,
in resolve
    module = __import__(self.module_name, fromlist=['__name__'], level=0)
  File "/usr/lib/python3/dist-packages/fava/cli.py", line 11, in <module>
    from fava.application import app
  File "/usr/lib/python3/dist-packages/fava/application.py", line 35, in
<module>
    from flask_babel import Babel
  File "/usr/lib/python3/dist-packages/flask_babel/__init__.py", line 19, in
<module>
    from werkzeug import ImmutableDict
ImportError: cannot import name 'ImmutableDict' from 'werkzeug'
(/usr/lib/python3/dist-packages/werkzeug/__init__.py)
--8<--

Turns out werkzeug was recently updated:

--8<--
python-werkzeug (1.0.1+dfsg1-2) unstable; urgency=medium

  * Uploading to unstable.

 -- Ondřej Nový <onovy@debian.org>  Tue, 14 Jul 2020 09:40:21 +0200
--8<--

The origin of the bug seems to be the use of deprecated exports from werkzeug,
which were removed:

https://github.com/pallets/werkzeug/commit/d50618e3651ad5d4d3118e903a040b733c4d0233#diff-9ab9cda90dbf882c5f053820bffc3d15

The fix appears to be:

  https://github.com/python-babel/flask-
babel/commit/fcc347b8e4c751f4cbe36d2a7652bc250f780c99



-- System Information:
Debian Release: bullseye/sid
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'unstable'), (500, 'testing'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.7.0-1-amd64 (SMP w/8 CPU threads)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages python3-flask-babel depends on:
ii  python3         3.8.2-3
ii  python3-babel   2.8.0+dfsg.1-3
ii  python3-flask   1.1.2-1
ii  python3-jinja2  2.11.2-1

python3-flask-babel recommends no packages.

Versions of packages python3-flask-babel suggests:
pn  python-flask-babel-doc  <none>

-- no debconf information