Error: cannot coerce a set to a string

[the-dr-lazy]

IDK that this is related to #188 or not!
BTW, I'm using Nix 2.3.3 and snack build inside nix-shell exits with the following error:

error: cannot coerce a set to a string, at /nix/store/43mrc82ajh3nxdjb7k9z6vslpjb2fjdx-source/lib/strings.nix:369:26

[nmattia]

Thanks for reporting! Can you share your config files?

[the-dr-lazy]

snack.nix

rec {
  ghc-version = "ghc865";
  ghcWithPackages = pkgs.haskellPackages.ghcWithPackages;
  pkgs = import ./nix {};
}

nix/default.nix

{ sources ? import ./sources.nix }:
let
  pkgs = import sources.nixpkgs { inherit config; overlays = [ overlay ]; };

  overlay = _: pkgs: {
    niv = (import sources.niv {}).niv;
    snack = (import sources.snack).snack-exe;
  };

  config = {
    packageOverrides = pkgs: {
      haskellPackages = pkgs.haskell.packages.ghc865.override {
        overrides = self: super: {
          xxx = super.callCabal2nix "xxx" ../. {};
          hasql-pool = pkgs.haskell.lib.dontCheck pkgs.haskellPackages.hasql-pool;
          record-dot-preprocessor = super.callCabal2nix "record-dot-preprocessor" sources.record-dot-preprocessor {};
        };
      };
    };
  };
in pkgs

[codygman]

I shared my config if this is related.