{
  description = "regular flolloping dot com";
  inputs = {
    haskellNix.url = "github:input-output-hk/haskell.nix";
    nixpkgs.follows = "haskellNix/nixpkgs-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };
  outputs = { self, nixpkgs, flake-utils, haskellNix }:
    flake-utils.lib.eachSystem [ "x86_64-linux" "x86_64-darwin" ] (system:
    let
      overlays = [
        haskellNix.overlay
        (final: prev: {
          rfgen =
            final.haskell-nix.project' {
              src = ./.;
              compiler-nix-name = "ghc8104";
            };
        })
      ];
      pkgs = import nixpkgs { inherit system overlays; };
      flake = pkgs.rfgen.flake {};
    in flake // {
      defaultPackage = flake.packages."rfgen:exe:rfgen-exe";
      devShell = pkgs.rfgen.shellFor {
        tools = {
          cabal = "latest";
          hlint = "latest";
          haskell-language-server = "latest";
        };
      };
    });
}


###### below this is output

@933.484 code/rfgen > nix build .#rfgen:exe:rfgen-exe
warning: Git tree '/home/thorn/code/rfgen' is dirty
trace: To make project.stack-nix a fixed-output derivation but not materialized, set `stack-sha256` to the output of the 'calculateMaterializedSha' script in 'passthru'.
trace: To materialize project.stack-nix entirely, pass a writable path as the `materialized` argument and run the 'updateMaterialized' script in 'passthru'.
trace: WARNING: `cleanSourceWith` called on /nix/store/ij58dr3dv7z0048aga1ql2xdryvsw63v-source without a `name`. Consider adding `name = "ij58dr3dv7z0048aga1ql2xdryvsw63v-source";`
error: --- Error --------------------------------------------------------------------------------- nix
builder for '/nix/store/6rrnnbx951j5fzkd8dnbyr9aqfyl7s7j-stack-repos.drv' failed with exit code 1; last 4 log lines:
  substituteStream(): WARNING: pattern '# nix-sha256:' doesn't match anything in file 'stack.yaml'
  stack-repos: AesonException "Error in $.resolver: expected String, but encountered Object"
  CallStack (from HasCallStack):
    error, called at lib/StackRepos.hs:36:15 in nix-tools-0.1.0.0-6VebEDwtbke5HHKMYxPZB7:StackRepos
(use '--show-trace' to show detailed location information)
@933.484 code/rfgen >