flattenReferencesGraph: use lib.fileset instead of gitignoreSource

{

  callPackage,

  lib,

  nix-gitignore,

  python3Packages,

}:

let

  inherit (lib) fileset;

  helpers = callPackage ./helpers.nix { };

  pythonPackages = python3Packages;

in

pythonPackages.buildPythonApplication {

  version = "0.1.0";

  pname = "flatten-references-graph";

  # Note: this uses only ./src/.gitignore

  src = nix-gitignore.gitignoreSource [ ] ./src;

  src = fileset.toSource {

    root = ./src;

    fileset = fileset.difference ./src (fileset.maybeMissing ./src/__pycache__);

  };

  propagatedBuildInputs = with pythonPackages; [

    igraph