1 files changed, 17 insertions, 8 deletions

diff --git a/shell.nix b/shell.nix
index a4274e7..27b7d06 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,9 +1,18 @@
-{ pkgs ? (import <nixpkgs> {})
-}:
+{ nixpkgs ? import <nixpkgs> {}, compiler ? "default" }:
 
-pkgs.lib.overrideDerivation (pkgs.haskellPackages.callPackage ./default.nix {}) (oldArgs: {
-  buildInputs = with pkgs; [ cabal2nix gup ];
-  shellHook = ''
-    export PROMPT_INFO=${oldArgs.name}
-  '';
-})
+let
+  inherit (nixpkgs) pkgs;
+
+  haskellPackages = if compiler == "default"
+                       then pkgs.haskellPackages
+                       else pkgs.haskell.packages.${compiler};
+
+  drv = haskellPackages.callPackage ./postdelay.nix {};
+in
+  pkgs.stdenv.lib.overrideDerivation drv.env (oldAttrs: {
+    buildInputs = oldAttrs.buildInputs ++ (with pkgs; [ cabal2nix gup ]);
+    shellHook = ''
+      ${oldAttrs.shellHook}
+      export PROMPT_INFO="${oldAttrs.name}"
+    '';
+  })