From 52c8d7c4ab0b2b2c97faa848b98dfc0ae9b69d7b Mon Sep 17 00:00:00 2001
From: Joel Taylor <me@joelt.io>
Date: Wed, 11 Feb 2015 14:30:37 -0800
Subject: [PATCH] Build GHC HEAD from git checkout

---
 pkgs/development/compilers/ghc/head.nix | 20 ++++++++++++++------
 pkgs/top-level/haskell-ng.nix           |  2 +-
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/pkgs/development/compilers/ghc/head.nix b/pkgs/development/compilers/ghc/head.nix
index cd1c89886291..9d7cd4482d2f 100644
--- a/pkgs/development/compilers/ghc/head.nix
+++ b/pkgs/development/compilers/ghc/head.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, ghc, perl, gmp, ncurses }:
+{ stdenv, fetchgit, ghc, perl, gmp, ncurses, autoconf, automake, happy, alex }:
 
 let
 
@@ -15,13 +15,21 @@ in
 stdenv.mkDerivation rec {
   version = "7.11.20150118";
   name = "ghc-${version}";
+  rev = "6ff3db92140e3ac8cbda50d1a4aab976350ac8c4";
 
-  src = fetchurl {
-    url = "http://deb.haskell.org/dailies/2015-01-18/ghc_${version}.orig.tar.bz2";
-    sha256 = "1zy960q2faq03camq2n4834bd748vkc15h83bapswc68dqncqj20";
+  src = fetchgit {
+    url = "git://git.haskell.org/ghc.git";
+    inherit rev;
+    sha256 = "1a1r3nw7x5rd8563770zcg1phm55vi3sxs2zwr91ik026n8jjba6";
   };
 
-  buildInputs = [ ghc perl ];
+  postUnpack = ''
+    pushd ghc-${builtins.substring 0 7 rev}
+    ./boot
+    popd
+  '';
+
+  buildInputs = [ ghc perl autoconf automake happy alex ];
 
   preConfigure = ''
     echo >mk/build.mk "${buildMK}"
@@ -39,7 +47,7 @@ stdenv.mkDerivation rec {
 
   # required, because otherwise all symbols from HSffi.o are stripped, and
   # that in turn causes GHCi to abort
-  stripDebugFlags = [ "-S" "--keep-file-symbols" ];
+  stripDebugFlags = [ "-S" ] ++ stdenv.lib.optional (!stdenv.isDarwin) "--keep-file-symbols";
 
   meta = {
     homepage = "http://haskell.org/ghc";
diff --git a/pkgs/top-level/haskell-ng.nix b/pkgs/top-level/haskell-ng.nix
index 220fca90a53f..cdf96879d6ac 100644
--- a/pkgs/top-level/haskell-ng.nix
+++ b/pkgs/top-level/haskell-ng.nix
@@ -18,7 +18,7 @@ rec {
     ghc763 = callPackage ../development/compilers/ghc/7.6.3.nix { ghc = compiler.ghc704Binary; gmp = pkgs.gmp.override { withStatic = true; }; };
     ghc784 = callPackage ../development/compilers/ghc/7.8.4.nix { ghc = compiler.ghc742Binary; gmp = pkgs.gmp.override { withStatic = true; }; };
     ghc7101 = callPackage ../development/compilers/ghc/7.10.1.nix { ghc = compiler.ghc784; gmp = pkgs.gmp.override { withStatic = true; }; };
-    ghcHEAD = callPackage ../development/compilers/ghc/head.nix { ghc = compiler.ghc784; gmp = pkgs.gmp.override { withStatic = true; }; };
+    ghcHEAD = callPackage ../development/compilers/ghc/head.nix { inherit (packages.ghc784) ghc happy alex; gmp = pkgs.gmp.override { withStatic = true; }; };
     ghc = compiler.ghc784;
 
   };