From fbdbe45393966eb4babd5ff305fce134b807149b Mon Sep 17 00:00:00 2001
From: Peter Simons <simons@cryp.to>
Date: Mon, 9 Dec 2013 14:23:56 +0100
Subject: [PATCH] haskell-pretty-show: the build requires happy version 1.19.x.

---
 pkgs/top-level/haskell-packages.nix | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index f34386fa180..f77199bd8af 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -1771,7 +1771,9 @@ let result = let callPackage = x : y : modifyPrio (newScope result.finalReturn x
 
   ppm = callPackage ../development/libraries/haskell/ppm {};
 
-  prettyShow = callPackage ../development/libraries/haskell/pretty-show {};
+  prettyShow = callPackage ../development/libraries/haskell/pretty-show {
+    happy = self.happy_1_19_2;
+  };
 
   punycode = callPackage ../development/libraries/haskell/punycode {};