old ghc pls

  nixpkgs = {
    config = {
      allowUnfree = true;
    };
    overlays = [
      (self: super: {
        haskell.compiler = self.haskell.compiler // { ghc802 = self.nur.repos.mpickering.ghc.ghc802; };
        nur = import (builtins.fetchTarball "https://github.com/nix-community/NUR/archive/master.tar.gz") {
          inherit pkgs;
        };
      })
    ];
  };

-----------------------------------------------------------------------------------

[~]$ sudo nixos-rebuild switch                                                                                      
building Nix...
building the system configuration...
error: attribute 'lib' missing, at /home/zfnmxt/repos/nixpkgs/pkgs/top-level/all-packages.nix:10079:16
(use '--show-trace' to show detailed location information)

-------------------------------
all-packages.nix:10079:16:

  shellcheck = haskell.lib.justStaticExecutables haskellPackages.ShellCheck;