How to get a multipackage environment with nix.

[locallycompact]

Hi. I've asked this on nixpkgs (https://github.com/NixOS/nixpkgs/issues/119175) but I imagine I'd find more answers here. I'm looking to get the idris.with-packages behaviour that I'm used to in nix.

I was able to build the pkg flake in this repository by instantiating it as a template, but not the pkgWithDep flake. I wanted to modify the pkgWithDep flake to just accept dependencies via fetchFromGitHub, but I don't see a mechanism to build those and install them to the correct directory, since everything on nixpkgs seems still specific to idris 1.

What is the right way to do this?

[claymager]

There isn't really a right way, yet. I'm working on it here (warning: unstable), but I'm holding off on adding it to nixpkgs until we get the next release. It requires some path changes that were made after v0.3.0.

[locallycompact]

Thank you very much. How do I call it?

[claymager]

# flake.nix
{
  inputs.userpkgs.url = github:claymager/nixpkgs/idris2;
  inputs.flake-utils.url = github:numtide/flake-utils;
  outputs = { self, userpkgs, flake-utils } :
    flake-utils.lib.eachSystem [ "x86_64-linux" ] (system:
      let pkgs = import userpkgs {inherit system; };
      in {
        devShell = pkgs.mkShell {
          buildInputs = [
            (pkgs.idris2.withPkgs (ps: [ ps.comonad ]) )
          ];
        };
      }
    );
}

I use something like that. As I said, unstable. and there's a few local paths in the branch atm for testing, but nix develop with that flake will grant you a shell with idris2-comonad.

You'll still need to explicitly call idris2 -p comonad in order to import Control.Comonad, if you're not using an ipkg file.

[stefan-hoeck]

Thanks, claymager, for your work on this nix-related stuff! I'm really looking forward to the day when we can use nix as a fully operating development environment for Idris2.

[mokshasoft]

Is there any change in Nix support for Idris2 yet?