Original report by Frederik Rietdijk (Bitbucket: FRidh, GitHub: FRidh).

If we have several backport packages (configparser, backports.shutil_get_terminal_size, backports.ssl_match_hostname), then we get an ImportError when we try to use these packages. At least

python -c 'import backports.shutil_get_terminal_size'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named 'backports.shutil_get_terminal_size'

We fixed the issue with
https://github.com/FRidh/nixpkgs/blob/d7378da0280ebc0b59d0d198fd86b2d4a9eace41/pkgs/development/python-modules/configparser/0001-namespace-fix.patch

Discussion on the issue.
NixOS/nixpkgs#23855