Fix #824 (#824)

[ju1m]

This is an attempt to fix #824 by reusing self.sources in overlays/haskell.nix instead of nix/sources.nix.
I'm not sure at all if this is a correct fix, but it works for me.

[skykanin]

I am having the same issue references in #824 and tried using your PR branch as the flake input to test if this fix works for me, but I'm still getting the same error. I'm not 100% sure if I did it correctly, here is my flake if you want to take a look. The relevant code is under inputs.haskellNix.url and defaultPackage.x86_64-linux.

[ju1m]

@skykanin By using import haskellNix you're bypassing the outputs of haskell.nix's flake.nix whose legacyPackages output provides the necessary localSystem:

haskell.nix/flake.nix

Line 34 in b35e9c7

(self.nixpkgsArgs // { localSystem = { inherit system; }; }));

My guess is that if you really need to import sources.nixpkgs-2003 yourself, you should do it as done in haskell.nix flake.nix. Something like:

      let nixpkgsArgs = haskellNix.nixpkgsArgs // { localSystem = { system = "x86_64-linux"; }; };
          nixpkgsSrc = haskellNix.sources.nixpkgs-2003;
          pkgs = import nixpkgsSrc nixpkgsArgs;
      in

But AFAICS the intended use is to just let pkgs = haskellNix.legacyPackages."x86_64-linux"; which currently uses a nixpkgs equal to nixpkgs-2003.
More generally, to see what flake outputs you can use, you can either read the flake.nix or list them with: nix flake show.

[skykanin]

Thanks for the help. Should I be using the master branch for the inputs.haskellNix.url? Because I'm now getting other errors and I'm wondering if maybe master isn't stable.

[ju1m]

@skykanin The master branch with the fix in the present PR work for me AFAICS. Here I'd say that your error message is likely due to your using of src = self instead of something more usual like src = ./..