From 330d874ee306aa6f56869195989e6264f01c2141 Mon Sep 17 00:00:00 2001
From: Nicholas Clarke <nick@topos.org.uk>
Date: Tue, 15 Aug 2017 15:00:15 +0100
Subject: [PATCH] Disable separate etc output for hscolour.

This is not needed, since `hscolour` has no output to `/etc`, and it
breaks certain old builds (see https://hydra.nixos.org/build/57925511)
because the older cabal used does not understand this flag.
---
 pkgs/development/haskell-modules/make-package-set.nix | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pkgs/development/haskell-modules/make-package-set.nix b/pkgs/development/haskell-modules/make-package-set.nix
index 5215fe4a552d..562042721e72 100644
--- a/pkgs/development/haskell-modules/make-package-set.nix
+++ b/pkgs/development/haskell-modules/make-package-set.nix
@@ -44,6 +44,7 @@ let
       isLibrary = false;
       doHaddock = false;
       hyperlinkSource = false;      # Avoid depending on hscolour for this build.
+      enableSeparateEtcOutput = false; # The flag to support this is missing in old versions of cabal.
       postFixup = "rm -rf $out/lib $out/share $out/nix-support";
     });
     cpphs = overrideCabal (self.cpphs.overrideScope (self: super: {