python3 opencv4 package breakage

[Pleune]

This overlay is breaking python3 opencv4 for me, I believe because your opencv4 package definition has removed pythonPackages arg set here https://github.com/NixOS/nixpkgs/blob/e7ca551dd57e3c87284b4c264f445cd0df4146dd/pkgs/top-level/python-packages.nix#L9778

I think you just need to redefine python3Packages.opencv4 with a pythonPackageExtensions so this nixpkgs definition is not used? and you can change it to python3Packages?

error:
       … while calling the 'head' builtin
         at /nix/store/brjzz8wv5k09bq0yrvhc1j4hd8677k21-source/lib/attrsets.nix:1574:11:
         1573|         || pred here (elemAt values 1) (head values) then
         1574|           head values
             |           ^
         1575|         else

       … while evaluating the attribute 'value'
         at /nix/store/brjzz8wv5k09bq0yrvhc1j4hd8677k21-source/lib/modules.nix:853:9:
          852|     in warnDeprecation opt //
          853|       { value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          854|         inherit (res.defsFinal') highestPrio;

       … while evaluating the option `system.build.toplevel':

       … while evaluating definitions from `/nix/store/brjzz8wv5k09bq0yrvhc1j4hd8677k21-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `warnings':

       … while evaluating definitions from `/nix/store/brjzz8wv5k09bq0yrvhc1j4hd8677k21-source/nixos/modules/system/boot/systemd.nix':

       … while evaluating the option `systemd.services.open-webui.serviceConfig':

       … while evaluating definitions from `/nix/store/brjzz8wv5k09bq0yrvhc1j4hd8677k21-source/nixos/modules/services/misc/open-webui.nix':

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: function 'anonymous lambda' called with unexpected argument 'pythonPackages'
       at /nix/store/0psxpc123l1v1d5gzb97ibqszqf6ccw4-source/packages/opencv4/package.nix:1:1:
            1| {
             | ^
            2|   blas,
       Did you mean python3Packages?

I fixed it with this overlay after yours.

final: prev: {
  cudaPackages = prev.cudaPackages_12_6;
  pythonPackagesExtensions = prev.pythonPackagesExtensions ++ [
    (pyFinal: pyPrev: {
      opencv4 = pyPrev.toPythonModule (prev.opencv4.override { enablePython = true; python3Packages = pyPrev; });
    })
  ];
}

Thanks for the large amount of work you are putting into this refactor ❤ . It seems to me like nixpkgs really needs it