python-configparser 3.5.0-1 breaks the python backports namespace

[Dan Kegel]

Installing python-configparser 3.5.0-1 breaks other python modules in the backports namespace.

https://bugs.launchpad.net/ubuntu/+source/python-pip/+bug/1812589 was filed against the wrong package; see also https://github.com/PiDelport/backports.os/issues/11

The problem was fixed upstream in June 2018
https://github.com/jaraco/configparser/pull/22
and the current verison (3.7.3) is ok.

To see the bug in action:

# apt update
# apt install python-pip
# su ubuntu
$ pip install --user backports.os
$ python -c "from backports import os" && echo ok
ok
$ sudo apt install python-configparser
$ Setting up python-configparser (3.5.0-1) ...
$ python -c "from backports import os" && echo ok
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: cannot import name os
$ sudo apt remove python-configparser
$ pip install configparser
https://github.com/jaraco/configparser/pull/22
$ pip list | grep configparser
configparser (3.7.3)
$ python -c "from backports import os" && echo ok
ok

Please pull a fix for this configparser problem into Ubuntu 18.04. Thanks!

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: python-configparser 3.5.0-1
ProcVersionSignature: Ubuntu 4.15.0-46.49-generic 4.15.18
Uname: Linux 4.15.0-46-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu Mar 21 13:57:17 2019
PackageArchitecture: all
SourcePackage: configparser
UpgradeStatus: Upgraded to bionic on 2018-04-30 (325 days ago)

[Dan Kegel (dank)]

See also https://github.com/jaraco/configparser/issues/17

I also verified that rebuilding the package python-configparser with the following patch, and installing that, fixes the problem here:

--- configparser-3.5.0.orig/setup.py
+++ configparser-3.5.0/setup.py
@@ -42,7 +42,6 @@ setup(
     py_modules=modules,
     package_dir={'': 'src'},
     packages=find_packages('src'),
- namespace_packages=['backports'],
     include_package_data=True,
     zip_safe=False,
     install_requires=requirements,
--- configparser-3.5.0.orig/src/backports/__init__.py
+++ configparser-3.5.0/src/backports/__init__.py
@@ -3,9 +3,3 @@

 from pkgutil import extend_path
 __path__ = extend_path(__path__, __name__)
-
-try:
- import pkg_resources
- pkg_resources.declare_namespace(__name__)
-except ImportError:
- pass

[Dan Kegel (dank)]

PPA https://launchpad.net/~dank/+archive/ubuntu/python-fixes/ now contains a python-configparser with that fix applied.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Jesse S (jdschwa)]

The upstream 3.5.x branch contains the fix too (currently 3.5.3).

The homepage is out-of-date on the configparser source package. It was moved to Github by the current maintainer.