GC Warning: Failed to expand heap by 4194304 KiB

error:

       … while evaluating attribute 'drv'

         at /nix/store/kwli1syc3yhl69wcl9690i8gwbawsj8x-filnix-experiment-0.13.3/lib/experiment/planner.nix:14:3:

           13| {

           14|   drv = p.drvPath;

             |   ^

           15|   name = p.name;

       … while evaluating the attribute 'drvPath'

         at /nix/store/dn9zga09bqy5asidv0np04fnp3hsrb8c-source/lib/customisation.nix:418:7:

          417|     // {

          418|       drvPath =

             |       ^

          419|         assert condition;

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: Package ‘dwarf-fortress-51.11’ in /nix/store/dn9zga09bqy5asidv0np04fnp3hsrb8c-source/pkgs/games/dwarf-fortress/game.nix:189 has an unfree license (‘unfreeRedistributable’), refusing to evaluate.

       a) To temporarily allow unfree packages, you can use an environment variable

          for a single invocation of the nix tools.

            $ export NIXPKGS_ALLOW_UNFREE=1

          Note: When using `nix shell`, `nix build`, `nix develop`, etc with a flake,

                then pass `--impure` in order to allow use of environment variables.

       b) For `nixos-rebuild` you can set

         { nixpkgs.config.allowUnfree = true; }

       in configuration.nix to override this.

       Alternatively you can configure a predicate to allow specific packages:

         { nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [

             "dwarf-fortress"

           ];

         }

       c) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add

         { allowUnfree = true; }

       to ~/.config/nixpkgs/config.nix.