{
  description = "A tool for organising a music library";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    utils.url = "github:numtide/flake-utils";
    flake-compat = {
      url = "github:edolstra/flake-compat";
      flake = false;
    };
  };

  outputs = { self, nixpkgs, utils, ... }:
    {
      hmModule = import ./hm-module.nix;

      overlay = final: prev:
        let system = final.system;
        in {
          musicutil = final.buildGoModule rec {
            pname = "musicutil";
            version = "latest";

            src = ./.;

            postPatch = ''
              substituteInPlace meta/meta.go --replace 'var ffmpeg_path = "ffmpeg"' 'var ffmpeg_path = "${final.ffmpeg}/bin/ffmpeg"'
              substituteInPlace meta/meta.go --replace 'var ffprobe_path = "ffprobe"' 'var ffprobe_path = "${final.ffmpeg}/bin/ffprobe"'
            '';

            vendorSha256 =
              "sha256-8mL467JTgtlmXKElDDtHRjkPpzvcB4G7qcPcLrA7Pzw=";

            doCheck = false;
            buildInputs = with final; [ ffmpeg ];
          };
        };
    } // utils.lib.eachSystem (utils.lib.defaultSystems) (system:
      let
        pkgs = import nixpkgs {
          inherit system;
          overlays = [ self.overlay ];
        };
      in {
        defaultPackage = self.packages."${system}".musicutil;
        packages.musicutil = pkgs.musicutil;

        apps = rec {
          musicutil = {
            type = "app";
            program = "${self.defaultPackage.${system}}/bin/musicutil";
          };
          default = musicutil;
        };

        defaultApp = self.apps."${system}".musicutil;

        devShell = pkgs.mkShell { buildInputs = with pkgs; [ go ffmpeg ]; };

        lib = pkgs.musicutil.lib;
      });
}