Some shell.nix

shell.nix

+let
+  pkgs-unstable = import (builtins.fetchTarball {
+    # Descriptive name to make the store path easier to identify
+    name = "nixos-unstable-2023-08-24";
+    # Commit hash for nixos-unstable as of 2018-09-12
+    url = "https://github.com/nixos/nixpkgs/archive/aa8aa7e2ea35ce655297e8322dc82bf77a31d04b.tar.gz";
+    # Hash obtained using `nix-prefetch-url --unpack <url>`
+    sha256 = "0bbv3y86kfpn02zh5vvdbkmnqyzagzbc1gzpvvlb6qbvgg639bf9";
+}) {};
+  pkgs = import <nixpkgs> {};
+  hls =pkgs-unstable.haskell-language-server.override { supportedGhcVersions = [ "96" ]; };
+in
+pkgs.mkShell {
+  packages = [ pkgs.haskell.compiler.ghc96 pkgs.cabal-install hls ];
+}