{
  description = "Pre-built CPU-only OpenCV packages for Python.  ";
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    opencv-python-related.url = "gitlab:all-dressed-programming/opencv-python-related";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils, opencv-python-related }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
        pythonPackages = pkgs.python312Packages // opencv-python-related.packages.${system}.python312Packages;
        virtual-env = pkgs.python312.withPackages (ps: [ ps.matplotlib
                                                         pythonPackages.opencv4
                                                         pythonPackages.boxmot
                                                         pythonPackages.ultralytics ]);

      in {
        packages = {
          env = virtual-env;
        };
        devShells.default = pkgs.mkShell { buildInputs = [ virtual-env pkgs.yt-dlp pkgs.ffmpeg_7]; };
      });
}