How to import

To import with flakes use

inputs = {
  polymc.url = "github:PolyMC/PolyMC";
};

...

nixpkgs.overlays = [ inputs.polymc.overlay.${system} ]; ## Within configuration.nix

To import without flakes use channels:

sudo -i nix-channel --add https://github.com/PolyMC/PolyMC/archive/master.tar.gz polymc
sudo -i nix-channel --update polymc

add <polymc> to imports in your configuration.nix

imports = [
  "<polymc>/packages/nix/overlay.nix"
];