duplicity: build fails for Black version conflict (required version 24 does not match 25.1.0)

[bittner]

Nixpkgs version

• Unstable (25.05)

Describe the bug

When running sudo nixos-rebuild switch --flake .#$HOST with my Flake-based NixOS setup that installs duplicity via deja-dup from the current latest master branch, tests with pytest run very long and I get a version error for the Black formatter:

Oh no! 💥 💔 💥 The required version `24` does not match the running version `25.1.0`!

This error from testing/test_code.py::CodeTest::test_black stems from the configuration introduced in b924af2.

This could be fixed by keeping the Black version in the duplicity test setup in sync with the installed system version. Although, as a Python developer, I don't see the value in running the Black formatter in the NixOS package build at all. This should run earlier, e.g. in a PR when the code change is originally made.

Hence, it might be preferable to add "test_black" to the list of disabledTests.

Steps to reproduce

1. Install deja-dup with your NixOS-config (GNOME-based target host)

Expected behaviour

The test_black test should not fail (or not run at all)

Screenshots

No response

Relevant log output

Additional context

No response

System metadata

• system: "x86_64-linux"
• host os: Linux 6.12.11, NixOS, 25.05 (Warbler), 25.05. ...
• multi-user?: yes
• version: nix-env (Nix) 2.24.11

Notify maintainers

@corngood

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