shell.nix

let
  # Override the java version of sbt package
  config = {
    packageOverrides = pkgs: rec {
      sbt = pkgs.sbt.overrideAttrs (
        old: rec {
          version = "1.3.12";

          patchPhase = ''
            echo -java-home ${pkgs.openjdk11} >> conf/sbtopts
          '';
        }
      );
    };
  };

  nixpkgs = fetchTarball {
    name   = "NixOS-unstable-08-06-2020";
    url    = "https://github.com/NixOS/nixpkgs-channels/archive/dcb64ea42e6.tar.gz";
    sha256 = "0i77sgs0gic6pwbkvk9lbpfshgizdrqyh18law2ji1409azc09w0";
  };
  pkgs = import nixpkgs { inherit config; };
in
  pkgs.mkShell {
    buildInputs = with pkgs; [
      jekyll # 4.1.0
      openjdk11 # 11.0.6-internal
      sbt # 1.3.12
    ];
  }