nixpkgs/pkgs/development/tools/build-managers/shards/shards.nix

{
  molinillo = {
    owner = "crystal-lang";
    repo = "crystal-molinillo";
    rev = "v0.2.0";
    sha256 = "0pzi8pbrjn03zgk3kbha2kqqq0crmr8gy98dr05kisafvbghzwnh";
  };
}