gistfile1.txt

{ config, pkgs, ... }:
let
  unstable = import <unstable> {};
in
{
  environment.systemPackages =
  let
    my-signal-cli = with pkgs; stdenv.mkDerivation rec {
      name = "signal-cli-${version}";
      version = "0.6.0";

      buildInputs = [ unstable.gradle ];

      src = fetchFromGitHub {
        owner  = "AsamK";
        repo   = "signal-cli";
        rev    = "86f5c99";
        sha256 = "12aw7j5754wb7p0zqgmpzav2f01l8lb0cs3ywpzpx0kz9scrkr51";
      };

      buildPhase = ''
        gradle build
      '';

      installPhase = ''
        export GRADLE_USR_HOME="/tmp"
        gradle installDist
        gradle distTar
      '';
    };
    in [ my-signal-cli ];
}