Update Nix configuration

Author: TravisCardwell

default.nix

@@ -1,2 +1,35 @@
-{ nixpkgs ? import <nixpkgs> {}, compiler ? "ghc883" }:
-nixpkgs.pkgs.haskell.packages.${compiler}.callPackage ./queue-sheet.nix { }
+let
+
+  nixpkgsRev = "cd63096d6d88";
+  compilerVersion = "ghc884";
+
+  githubTarball = owner: repo: rev:
+    builtins.fetchTarball { url = "https://github.com/${owner}/${repo}/archive/${rev}.tar.gz"; };
+
+  gitIgnore = pkgs.nix-gitignore.gitignoreSourcePure;
+
+  config = {
+    packageOverrides = super: let self = super.pkgs; in rec {
+      haskell = super.haskell // {
+        packageOverrides = self: super: {
+          haskell-nix = super.callCabal2nix "haskell-nix" (gitIgnore [./.gitignore] ./.) {};
+        };
+      };
+    };
+  };
+
+  pkgs = import (githubTarball "NixOS" "nixpkgs" nixpkgsRev) { inherit config; };
+  compilerSet = pkgs.haskell.packages."${compilerVersion}";
+
+in {
+
+  inherit pkgs;
+
+  shell = compilerSet.shellFor {
+    packages = p: [p.haskell-nix];
+    buildInputs = with pkgs; [
+      compilerSet.cabal-install
+    ];
+  };
+
+}

queue-sheet.nix

@@ -1,2 +1 @@
-{ nixpkgs ? import <nixpkgs> {}, compiler ? "ghc883" }:
-(import ./default.nix { inherit nixpkgs compiler; }).env
+(import ./default.nix).shell