{ description = "basic test framework for idris 2";

  inputs = {
    nixpkgs.url = "nixpkgs/21.11";

    flake-utils = {
      url = "github:numtide/flake-utils";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    idris2-pkgs = {
      url = "github:claymager/idris2-pkgs";
      inputs.nixpkgs.follows = "nixpkgs";
      inputs.flake-utils.follows = "flake-utils";
    };
  };

  outputs = { self, nixpkgs, idris2-pkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs {
          inherit system;
          overlays = [ idris2-pkgs.overlay ];
        };
        builders = pkgs.idris2-pkgs._builders;

        packages = let ipkg = builders.idrisPackage; in rec {
          tap         = ipkg ./.       { };
          tap-example = ipkg ./example { extraPkgs = packages; };
        };

        devShells =
          let mkDevShell = _: pkg:
                pkgs.mkShell { buildInputs = [ (builders.devEnv pkg) ]; };
          in builtins.mapAttrs mkDevShell packages;
      in {
        inherit packages devShells;
        defaultPackage = packages.tap;
        devShell       = devShells.tap;
      }
    );
}