isle/nix/pkgs.nix

rec {

  overlays = [

    # Make buildGoModules use static compilation by default
    (final: prev: let
      buildArgs = {
        doCheck = false;
        CGO_ENABLED=0;
        tags = [ "netgo" "timetzdata" ];
        ldflags = [ "-w" "-extldflags=-static" ];

        # Not sure why buildGoModule doesn't handle this correctly.
        GOARM = if prev.stdenv.hostPlatform.parsed.cpu.name == "armv6l"
          then "6,hardfloat"
          else null;
      };
    in {
      buildGoModule = args: prev.buildGoModule (buildArgs // args);
    })

    # for whatever reason git checks fail when flake is being used (or maybe
    # it's crossSystem's fault)
    (final: prev: {
      git = prev.git.overrideAttrs (oldAttrs: {
        installCheckPhase = ''
          # noop
         '';
      });
    })

  ];

  version = "24.05";
  rev = "5646423bfac84ec68dfc60f2a322e627ef0d6a95";

  src = fetchTarball {
    name = "nixpkgs-${version}";
    url = "https://github.com/NixOS/nixpkgs/archive/${rev}.tar.gz";
    sha256 = "sha256:1lr1h35prqkd1mkmzriwlpvxcb34kmhc9dnr48gkm8hh089hifmx";
  };

  lib = import "${src}/lib";

  crossSystems = {
    "x86_64-linux" = {config = "x86_64-linux";};
    "aarch64-linux" = lib.systems.examples.aarch64-multiplatform;
    "i686-linux" = {config = "i686-linux";};
    "armv6l-linux" = lib.systems.examples.raspberryPi;
  };

  supportedSystems = builtins.attrNames crossSystems;

  default = {
    buildSystem,
    hostSystem ? buildSystem,
  }: import src ({

    inherit overlays;
    system = buildSystem;

  } // (if buildSystem == hostSystem then {} else {

    # The nixpkgs cache doesn't have any packages where cross-compiling has been
    # enabled, even if the target platform is actually the same as the build
    # platform (and therefore it's not really cross-compiling). So we only set
    # up the cross-compiling config if the target platform is different.
    crossSystem = builtins.getAttr hostSystem crossSystems;
  }));
}