Trouble using PySide6 as dependency

I previously packaged protonup-qt, before PySide6 was packaged, using the appimage. Now that PySide6 is available I would like to update the package to be built from source. Unfortunately, I am running into a problem using PySide6 as a dependency.

The error I get is:

> ERROR: Could not find a version that satisfies the requirement PySide6-Essentials>=6.3.0 (from protonup-qt) (from versions: none)
> ERROR: No matching distribution found for PySide6-Essentials>=6.3.

The current package looks like this:

{ lib
, python3
, fetchFromGitHub
}:

python3.pkgs.buildPythonApplication rec {
  pname = "protonup-qt";
  version = "2.8.0";
  format = "pyproject";

  src = fetchFromGitHub {
    owner = "DavidoTek";
    repo = "ProtonUp-Qt";
    rev = "v${version}";
    hash = "sha256-/1+5HrVRPBdkhS2aFMwG2djexaEZC1bZ49nfQs98elI=";
  };

  propagatedBuildInputs = with python3.pkgs; [
    inputs
    pyside6
    pyxdg
    pyyaml
    requests
    setuptools
    steam
    vdf
    zstandard
  ];

  pythonImportsCheck = [ "protonup-qt" ];

  meta = with lib; {
    homepage = "https://davidotek.github.io/protonup-qt/";
    description = "https://github.com/DavidoTek/ProtonUp-Qt/";
    license = licenses.gpl3;
    platforms = [ "x86_64-linux" ];
    maintainers = with maintainers; [ michaelBelsanti ];
  };
}

Also, what is the correct method for wrapping this package? Does this suffice?

  preFixup = ''
    makeWrapperArgs+=("''${qtWrapperArgs[@]}")
  '';

Here’s a link to the PR if anyone is willing to take a look at it. It includes a few new dependencies that aren’t currently in Nixpkgs.

I’m having the same issue here packaging something else:

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";

    wwrando = {
      url = "github:LagoLunatic/wwrando?ref=1.10.0";
      flake = false;
    };
  };


  outputs = { self, nixpkgs, wwrando }:
    let
      supportedSystems = [ "x86_64-linux" ];
      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
      pkgs = forAllSystems (system: nixpkgs.legacyPackages.${system});
    in
    {
      packages = forAllSystems (system: 
      let
        syspkgs = pkgs.${system};
        pythonpkgs = syspkgs.python3Packages;
      in
      {
        default = pythonpkgs.buildPythonApplication {
          pname = "wwrando";
          version = "1.10.0";
          src = wwrando;
          format = "pyproject";
          buildInputs = with syspkgs.qt6; [
            wrapQtAppsHook
          ];
          propagatedBuildInputs = with pythonpkgs; [
            pyyaml
            pyside6
            pillow
            appdirs
            certifi
            setuptools
          ];
          preBuild = ''
            cat > pyproject.toml << EOF
            '' + builtins.readFile ./pyproject.toml + "EOF";
        };
      });
    };
}