{
  description = "A very basic flake";

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

  outputs = {
    self,
    nixpkgs,
    flake-utils,
    android-nixpkgs
  }:
    flake-utils.lib.eachDefaultSystem (system: let
      pkgs = import nixpkgs {
        inherit system;
        config = {
          android_sdk.accept_license = true;
          allowUnfree = true;
        };
      };
      texlive-env = (pkgs.texlive.combine {
        inherit (pkgs.texlive) scheme-basic
        xetex
        float xcolor varwidth fancyvrb multirow hanging adjustbox stackengine
        enumitem alphalph ulem xkeyval collectbox etoolbox wasysym sectsty
        tocloft newunicodechar caption etoc psnfss metafont helvetic courier
        wasy wasy-type1
        ;
      });
      androidSdk = android-nixpkgs.sdk.${system} (sdkPkgs: with sdkPkgs; [
        build-tools-30-0-3
        build-tools-33-0-0
        cmdline-tools-latest
        platform-tools
        platforms-android-33
      ]);
    in rec {
      formatter = pkgs.alejandra;
      devShells.default =
        pkgs.mkShell {
          buildInputs = with pkgs; [
            androidSdk
            glibc
            doxygen
            graphviz
            texlive-env
          ];
          # override the aapt2 that gradle uses with the nix-shipped version
          GRADLE_OPTS = "-Dorg.gradle.project.android.aapt2FromMavenOverride=${androidSdk}/share/android-sdk/build-tools/33.0.0/aapt2";
        };
      packages = rec {
        invtracker-deps = pkgs.stdenv.mkDerivation {
          name = "invtracker-deps";
          src = self;
          nativeBuildInputs = with pkgs; [gradle openjdk_headless perl];
          buildPhase = ''
            export GRADLE_USER_HOME=$(mktemp -d)
            # Fetch the maven deps
            gradle --no-daemon --info -Dorg.gradle.java.home=${pkgs.openjdk_headless} --write-verification-metadata sha256
          '';
          installPhase = ''
            find $GRADLE_USER_HOME/caches/modules-2 -type f -regex '.*\.\(aar\|jar\|pom\|module\)$' \
              | perl -pe 's#(.*/([^/]+)/([^/]+)/([^/]+)/[0-9a-f]{30,40}/([^/\s]+))$# ($x = $2) =~ tr|\.|/|; "install -Dm444 $1 \$out/maven/$x/$3/$4/$5" #e' \
              | sh
          '';
          outputHashAlgo = "sha256";
          outputHashMode = "recursive";
          outputHash = "sha256-Rxd9z/HQpIBVixzgbj7tq0/WfqGLytPmN1vpNFN6BgI=";
        };
        invtracker-server = pkgs.stdenv.mkDerivation {
          pname = "invtracker-server";
          version = self.lastModifiedDate;
          src = self;
          nativeBuildInputs = with pkgs; [gradle openjdk_headless];
          buildPhase = ''
            sed -i 's#gradlePluginPortal..#maven { url "${invtracker-deps}/maven" }#' settings.gradle
            sed -i 's#google..#maven { url "${invtracker-deps}/maven" }#' settings.gradle

            export GRADLE_USER_HOME=$(mktemp -d)
            gradle --offline --no-daemon --info -Dorg.gradle.java.home=${pkgs.openjdk_headless} server:installDist
          '';
          installPhase = ''
            cp -rv server/build/install/server $out/
          '';
        };
        invtracker-client =
          pkgs.stdenv.mkDerivation rec {
          pname = "invtracker-client";
          version = self.lastModifiedDate;
          src = self;
          nativeBuildInputs = with pkgs; [gradle openjdk_headless androidSdk ];
          buildPhase = ''
            sed -i 's#gradlePluginPortal..#maven { url "${invtracker-deps}/maven" }#' settings.gradle
            sed -i 's#google..#maven { url "${invtracker-deps}/maven" }#' settings.gradle

            export GRADLE_USER_HOME=$(mktemp -d)
            gradle --offline --no-daemon --info -Dorg.gradle.project.android.aapt2FromMavenOverride=${androidSdk}/share/android-sdk/build-tools/33.0.0/aapt2 -Dorg.gradle.java.home=${pkgs.openjdk_headless} app:packageDebug
          '';
          installPhase = ''
            mkdir $out
            cp app/build/outputs/apk/debug/debug.apk $out/app.apk
            mkdir $out/nix-support
            echo "file binary-dist $out/app.apk" > $out/nix-support/hydra-build-products
            echo "$pname-$version" > $out/nix-support/hydra-release-name
          '';
        };
        invtracker-docs = pkgs.callPackage ./doc.nix { inherit self texlive-env; };
      };

      hydraJobs =
        if system == "x86_64-linux"
        then devShells // packages
        else {};
    });
}