From 943bc26762793b21e0c84ee523c1f5fe23bb624d Mon Sep 17 00:00:00 2001
From: Peter Simons <simons@cryp.to>
Date: Wed, 1 Apr 2015 13:52:21 +0200
Subject: [PATCH] haskell-generic-builder: when replacing an edited Cabal file,
 show the download URL rather than the store path

---
 pkgs/development/haskell-modules/generic-builder.nix | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/haskell-modules/generic-builder.nix b/pkgs/development/haskell-modules/generic-builder.nix
index 30109b9a249..dfc7efe811b 100644
--- a/pkgs/development/haskell-modules/generic-builder.nix
+++ b/pkgs/development/haskell-modules/generic-builder.nix
@@ -55,8 +55,9 @@ let
 
   isGhcjs = ghc.isGhcjs or false;
 
+  newCabalFileUrl = "http://hackage.haskell.org/package/${pname}-${version}/revision/${revision}.cabal";
   newCabalFile = fetchurl {
-    url = "http://hackage.haskell.org/package/${pname}-${version}/revision/${revision}.cabal";
+    url = newCabalFileUrl;
     sha256 = editedCabalFile;
     name = "${pname}-${version}-r${revision}.cabal";
   };
@@ -134,7 +135,7 @@ stdenv.mkDerivation ({
   LANG = "en_US.UTF-8";         # GHC needs the locale configured during the Haddock phase.
 
   prePatch = optionalString (editedCabalFile != null) ''
-    echo "Replacing Cabal file with edited version ${newCabalFile}."
+    echo "Replace Cabal file with edited version from ${newCabalFileUrl}."
     cp ${newCabalFile} ${pname}.cabal
   '' + optionalString jailbreak ''
     echo "Running jailbreak-cabal to lift version restrictions on build inputs."