From 981dbc35d14676e804462136a7698c6fcfe694fc Mon Sep 17 00:00:00 2001
From: Charles Strahan <charles.c.strahan@gmail.com>
Date: Sat, 28 Mar 2015 23:45:28 -0400
Subject: [PATCH] ghc-7.10.1: cherry-pick Cabal bugfix for GHCJS

---
 pkgs/development/compilers/ghc/7.10.1.nix | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/pkgs/development/compilers/ghc/7.10.1.nix b/pkgs/development/compilers/ghc/7.10.1.nix
index 629ac69d36f..5bec1fa3f55 100644
--- a/pkgs/development/compilers/ghc/7.10.1.nix
+++ b/pkgs/development/compilers/ghc/7.10.1.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, ghc, perl, gmp, ncurses, libiconv }:
+{ stdenv, fetchurl, fetchpatch, ghc, perl, gmp, ncurses, libiconv }:
 
 let
 
@@ -13,6 +13,13 @@ let
     ''}
   '';
 
+  # We patch Cabal for GHCJS. See: https://github.com/haskell/cabal/issues/2454
+  # This should be removed when GHC includes Cabal > 1.22.2.0
+  cabalPatch = fetchpatch {
+    url = https://github.com/haskell/cabal/commit/f11b7c858bb25be78b81413c69648c87c446859e.patch;
+    sha256 = "1z56yyc7lgc78g847qf19f5n1yk054pzlnc2i178dpsj0mgjppyb";
+  };
+
 in
 
 stdenv.mkDerivation rec {
@@ -28,9 +35,13 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
-  # We patch Cabal for GHCJS. See: https://github.com/haskell/cabal/issues/2454
+  postPatch = ''
+    pushd libraries/Cabal
+    patch -p1 < ${cabalPatch}
+    popd
+  '';
+
   preConfigure = ''
-    sed -i 's/HcPkg.useSingleFileDb = .*/HcPkg.useSingleFileDb = False/' libraries/Cabal/Cabal/Distribution/Simple/GHCJS.hs
     echo >mk/build.mk "${buildMK}"
     sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
   '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''