From 4541b1090491a7ab74d74a5ebee31bd3ccf1be63 Mon Sep 17 00:00:00 2001
From: Matthew Pickering <matthewtpickering@gmail.com>
Date: Sat, 24 Dec 2016 17:37:58 +0000
Subject: [PATCH] Refactor ghcHEAD postPatch / preConfigure phases

This is for GHC developers using NixOS where patchShebangs is
inconvenient as it dirties the tree but unnecessary for compilation.
---
 pkgs/development/compilers/ghc/head.nix | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/pkgs/development/compilers/ghc/head.nix b/pkgs/development/compilers/ghc/head.nix
index 0deabd0fa98..0581038d18d 100644
--- a/pkgs/development/compilers/ghc/head.nix
+++ b/pkgs/development/compilers/ghc/head.nix
@@ -27,19 +27,18 @@ in stdenv.mkDerivation (rec {
     sha256 = "0rk6xy7kgxx849nprq1ji459p88nyy93236g841m5p6mdh7mmrcr";
   };
 
-  postPatch = ''
+  postPatch = "patchShebangs .";
+
+  preConfigure = ''
     echo ${version} >VERSION
     echo ${rev} >GIT_COMMIT_ID
-    patchShebangs .
     ./boot
-  '';
+  '' + commonPreConfigure ;
 
   buildInputs = commonBuildInputs;
 
   enableParallelBuilding = true;
 
-  preConfigure = commonPreConfigure;
-
   configureFlags = [
     "CC=${stdenv.cc}/bin/cc"
     "--with-gmp-includes=${gmp.dev}/include" "--with-gmp-libraries=${gmp.out}/lib"