From c460fa95fb033cde456591409d755eb472a29f3e Mon Sep 17 00:00:00 2001
From: Peter Simons <simons@cryp.to>
Date: Mon, 30 Mar 2015 04:03:55 +0200
Subject: [PATCH] haskell-mtl-compat: fix build with ghc 7.6.x.

---
 pkgs/development/haskell-modules/configuration-ghc-7.6.x.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pkgs/development/haskell-modules/configuration-ghc-7.6.x.nix b/pkgs/development/haskell-modules/configuration-ghc-7.6.x.nix
index d853e9265ba4..5285484d2ffa 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-7.6.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-7.6.x.nix
@@ -70,4 +70,7 @@ self: super: {
   contravariant = addBuildDepend super.contravariant self.tagged;
   reflection = dontHaddock (addBuildDepend super.reflection self.tagged);
 
+  # The compat library is empty in the presence of mtl 2.2.x.
+  mtl-compat = dontHaddock super.mtl-compat;
+
 }