update default.nix

default.nix

@@ -1,10 +1,14 @@
 { pkgs ? import <nixpkgs> {} }:
 with pkgs;
-{
+let
+  composerEnv = import ./composer-env.nix {
+    inherit (pkgs) stdenv lib writeTextFile fetchurl php unzip phpPackages;
+  };
   phpPack = import ./php-packages.nix {
         inherit (pkgs) fetchurl fetchgit fetchhg fetchsvn;
     };
-  source = stdenv.mkDerivation {
+in
+stdenv.mkDerivation {
   name = "searchanddisplace-core-source";
   src = builtins.fetchGit {
    url = "https://git.law/newroco/searchanddisplace-ingest.git";
@@ -16,5 +20,4 @@ with pkgs;
     cp -r $src $out
     composer install
   '';
-    };
 }