{
  description = "Robossembler Development Environments on Nix";
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs?ref=master";
    flake-utils.url = "github:numtide/flake-utils";
    ros-flake.url = "github:lopsided98/nix-ros-overlay?ref=staging";
  };

  outputs = { self, nixpkgs, ros-flake, flake-utils }:
    flake-utils.lib.eachDefaultSystem
      (system:
        let
          pkgs = nixpkgs.legacyPackages.${system};
          ros = ros-flake.legacyPackages.${system};

          # overrided packages and attributes for nix-ros-overlay
          humble-overrided = ros.humble.overrideScope (final: prev: {
            # remove after update github:lopsided98/nixpkgs/nix-ros for https://github.com/NixOS/nixpkgs/pull/224099
            behaviortree-cpp-v3 = prev.behaviortree-cpp-v3.overrideAttrs (old: { 
              propagatedBuildInputs = old.propagatedBuildInputs ++ [ pkgs.zeromq ];
            });
            moveit-core = prev.moveit-core.overrideAttrs (old: { 
              propagatedBuildInputs = old.propagatedBuildInputs ++ [ prev.tf2-kdl ];
            });
            moveit-kinematics = prev.moveit-kinematics.overrideAttrs (old: { 
              propagatedBuildInputs = old.propagatedBuildInputs ++ [ final.moveit-ros-planning ];
            });
          });
          
          # robossembler custom packages; defined here for share between devShells and packages
          blender = pkgs.callPackage ./pkgs/misc/blender { };
          bpy = pkgs.python3Packages.callPackage ./pkgs/development/python-modules/bpy { };
          pysdf = pkgs.python3Packages.callPackage ./pkgs/development/python-modules/pysdf { };
          mayo = pkgs.libsForQt5.callPackage ./pkgs/misc/mayo { };
          darknet = pkgs.callPackage ./pkgs/misc/darknet { };
          fstl = pkgs.libsForQt5.callPackage ./pkgs/misc/fstl { };
          open3d = pkgs.callPackage ./open3d.nix { };
          unified-planning = pkgs.python3Packages.callPackage ./pkgs/development/python-modules/unified-planning { };
          blenderproc = pkgs.python3Packages.callPackage ./blenderproc.nix { };
          webdataset = pkgs.python3Packages.callPackage ./pkgs/development/python-modules/webdataset { };
          ansitable = pkgs.python3Packages.callPackage ./pkgs/development/python-modules/ansitable { };
          megapose6d = pkgs.python3Packages.callPackage ./pkgs/development/python-modules/megapose6d { webdataset = webdataset; };
          spatialmath = pkgs.python3Packages.callPackage ./pkgs/development/python-modules/spatialmath { ansitable = ansitable; };
          slic3r = pkgs.callPackage ./pkgs/misc/slic3r { };
        in
        {
          inherit pkgs;

          rlib = import ./. { 
            inherit (pkgs.stdenv) mkDerivation;
            inherit (pkgs) lib;
            inherit mayo;
            inherit (pkgs.libsForQt5) wrapQtAppsHook;
          };

          packages = {
            inherit mayo blender bpy pysdf fstl darknet unified-planning slic3r megapose6d;
            gazebo = ros.humble.gazebo;
          };

          devShells.ros = 
            pkgs.mkShell {
              buildInputs = (with humble-overrided; [
                ros2run
                rmw-fastrtps-dynamic-cpp
                urdf
                ament-pep257
                ament-lint-auto
                xacro
                ament-cmake
                rclcpp-action
                tf2
                action-msgs
                ament-copyright
                pythonPackages.pytest
                rosidl-default-generators
                behaviortree-cpp-v3
                geometry-msgs
                rosidl-default-runtime
                rclpy
                std-msgs
                ament-lint-common
                ament-flake8
                tf2-ros
                rclcpp
                moveit-core
                moveit-msgs
                moveit-ros-planning
                moveit-ros-planning-interface
                gazebo-ros2-control
                plansys2-bringup
                image-transport
                cv-bridge
                example-interfaces
              ]) ++ (with pkgs; [ nlohmann_json glog lua5_3_compat ]);
              RMW_IMPLEMENTATION = "rmw_fastrtps_dynamic_cpp";
            };

          devShells.all = pkgs.mkShell { 
            packages = [ mayo blender bpy pysdf fstl darknet slic3r ];
          };

          devShells.rbs-framework =
            let
              my-python-packages = p: with p; [ 
                bpy
                pysdf
                unified-planning 
                pybullet
                scipy
                spatialmath
              ];
            in
            pkgs.mkShell {
              packages = [ (pkgs.python3.withPackages my-python-packages) pkgs.freecad mayo ];
              buildInputs = [  ];

              # Run when the shell is started up
              shellHook = ''
                ${pkgs.python3}/bin/python --version
              '';
            };
        }
      );

  nixConfig = {
    extra-substituters = [ "https://ros.cachix.org" "https://robossembler.cachix.org" ];
    extra-trusted-public-keys = [ 
      "ros.cachix.org-1:dSyZxI8geDCJrwgvCOHDoAfOm5sV1wCPjBkKL+38Rvo="
      "robossembler.cachix.org-1:56jBJHroRQSGpZFkW8XMquuzQTjAF/XTo6MogmBM7SQ="
    ];
  };
}