shell.nix

let
  pkgs =
    import (
      builtins.fetchTarball {
        url = "https://github.com/nixos/nixpkgs/archive/d934204a0f8d9198e1e4515dd6fec76a139c87f0.tar.gz";
        sha256 = "1zfby2jsfkag275aibp81bx1g1cc305qbcy94gqw0g6zki70k1lx";
      }
    ) {
      overlays = [
        (final: prev: {
          pony = prev.pony.overrideAttrs (oldAttrs: {
            patches =
              oldAttrs.patches
              or []
              ++ [
                (final.fetchpatch {
                  url = "https://patch-diff.githubusercontent.com/raw/nixos/nixpkgs/pull/290383.patch";
                  hash = "sha256-6LOYLDLtVCHxNdHAWv3zhlCsljIpi//RJb9XVLGD5hM=";
                })
              ];
          });
        })
      ];
    };
in
  pkgs.mkShell {
    packages = [
      pkgs.mutmut
    ];
  }