From 843aee694d7fe895f4cd8f3efb6eee15be2fe2d7 Mon Sep 17 00:00:00 2001
From: Peter Simons <simons@cryp.to>
Date: Thu, 22 Jan 2015 22:59:40 +0100
Subject: [PATCH] haskell-utf8-string: fix build with ghc 6.12.x

The "sed" command stopped working recently. I have no idea why, but the
new patch is simpler anyway.
---
 pkgs/development/haskell-modules/configuration-ghc-6.12.x.nix | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/pkgs/development/haskell-modules/configuration-ghc-6.12.x.nix b/pkgs/development/haskell-modules/configuration-ghc-6.12.x.nix
index 33c7060f5f45..764064ae903e 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-6.12.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-6.12.x.nix
@@ -59,9 +59,7 @@ self: super: {
   ChasingBottoms = dontHaddock super.ChasingBottoms;
 
   # https://github.com/glguy/utf8-string/issues/9
-  utf8-string = overrideCabal super.utf8-string (drv: {
-    patchPhase = "sed -ir -e 's|Extensions: | Extensions: UndecidableInstances, |' utf8-string.cabal";
-  });
+  utf8-string = appendConfigureFlag super.utf8-string "--ghc-option=-XUndecidableInstances";
 
   # https://github.com/haskell/HTTP/issues/80
   HTTP = doJailbreak super.HTTP;