{ sources ? import ./npins, pkgs ? import sources.nixpkgs {} }:
{
  overlay = self: super: 
  let
    inherit (super) lib;
  in
  {
    ofborg = super.rustPlatform.buildRustPackage {
      name = "ofborg";
      src = super.nix-gitignore.gitignoreSource [ ] ./.;

      nativeBuildInputs = with pkgs; [
        pkg-config
        rustPackages.clippy
      ];

      buildInputs = lib.optionals super.stdenv.isDarwin (with pkgs; [
        darwin.apple_sdk.frameworks.Security
        darwin.apple_sdk.frameworks.CoreFoundation
      ]);

      preBuild = ''
        cargo clippy
      '';

      doCheck = false; # Tests require access to a /nix/ and a nix daemon
      checkInputs = with super; [
        lix
      ];

      cargoLock = {
        lockFile = ./Cargo.lock;
      };
    };
  };
  packages = {
    ofborg = pkgs.rustPlatform.buildRustPackage {
      name = "ofborg";
      src = pkgs.nix-gitignore.gitignoreSource [ ] ./.;

      nativeBuildInputs = with pkgs; [
        pkg-config
        rustPackages.clippy
      ];

      buildInputs = with pkgs; [
      ] ++ lib.optionals pkgs.stdenv.isDarwin (with pkgs; [
        darwin.apple_sdk.frameworks.Security
        darwin.apple_sdk.frameworks.CoreFoundation
      ]);

      preBuild = ''
        cargo clippy
      '';

      doCheck = false; # Tests require access to a /nix/ and a nix daemon
      checkInputs = with pkgs; [
        lix
      ];

      cargoLock = {
        lockFile = ./Cargo.lock;
      };
    };
  };

  shell = pkgs.mkShell {
    name = "ofborg-devenv";
    RABBITMQ_CONFIG_FILE = pkgs.writeText "rabbitmq-dev.conf" ''
      listeners.tcp.1=:::5672
    '';
    TRIVIAL_PASSWORD = pkgs.writeText "trivial-password.txt" "test";
    RABBITMQ_LOGS = "-";
    RUST_SRC_PATH = pkgs.rustPlatform.rustLibSrc;
    packages = with pkgs; [
      lix
      gitFull
      nix-prefetch-git
      rustc
      cargo
      cargo-edit
      cargo-outdated
      clippy
      rustfmt
      pkg-config
      rabbitmq-server
      hivemind
    ];

    postHook = ''
      checkPhase() (
          cd "${builtins.toString ./.}/ofborg"
          set -x
          cargo fmt
          git diff --exit-code
          cargofmtexit=$?

          cargo clippy
          cargoclippyexit=$?

          cargo build && cargo test
          cargotestexit=$?

          sum=$((cargofmtexit + cargoclippyexit + cargotestexit))
          exit $sum
      )
    '';

    shellHook = ''
      export RABBITMQ_MNESIA_BASE="$(git rev-parse --show-toplevel)/.rabbitmq-data";
      export STATE_DIRECTORY="$(git rev-parse --show-toplevel)/.ofborg-state"
      mkdir -p "$STATE_DIRECTORY"
      mkdir -p "$RABBITMQ_MNESIA_BASE"
    '';

    RUSTFLAGS = "-D warnings";
    RUST_BACKTRACE = "1";
    RUST_LOG = "ofborg=debug";
    NIX_PATH = "nixpkgs=${pkgs.path}";
  };
}