Fixes for tests

Author: hamishmack

test/cabal-doctests/default.nix

@@ -1,5 +1,5 @@
 # Test a package set
-{ stdenv, util, cabalProject', haskellLib, gmp6, zlib, recurseIntoAttrs, runCommand, testSrc, compiler-nix-name }:
+{ stdenv, util, cabalProject', haskellLib, gmp6, zlib, recurseIntoAttrs, runCommand, testSrc, compiler-nix-name, buildPackages }:
 
 with stdenv.lib;