From 9f1a3a4b0ff90869c41efcb72ba1610dd05d10d1 Mon Sep 17 00:00:00 2001
From: "William A. Kennington III" <william@wkennington.com>
Date: Sat, 5 Sep 2015 01:35:13 -0700
Subject: [PATCH] pond: Fix x86_64 optimizations to be correctly applied to
 only x86_64

---
 pkgs/development/libraries/dclxvi/default.nix |  2 +-
 pkgs/top-level/go-packages.nix                | 12 +++++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/pkgs/development/libraries/dclxvi/default.nix b/pkgs/development/libraries/dclxvi/default.nix
index 1b8528dd08bb..6207f3d20382 100644
--- a/pkgs/development/libraries/dclxvi/default.nix
+++ b/pkgs/development/libraries/dclxvi/default.nix
@@ -22,6 +22,6 @@ stdenv.mkDerivation {
     homepage = "https://github.com/agl/dclxvi";
     description = "Naehrig, Niederhagen and Schwabe's pairings code, massaged into a shared library";
     maintainers = with maintainers; [ wkennington ];
-    platforms = platforms.all;
+    platforms = platforms.x86_64;
   };
 }
diff --git a/pkgs/top-level/go-packages.nix b/pkgs/top-level/go-packages.nix
index 3cdf30300567..6a83cc46701d 100644
--- a/pkgs/top-level/go-packages.nix
+++ b/pkgs/top-level/go-packages.nix
@@ -2090,15 +2090,21 @@ let
     doCheck = false; # bad import path in tests
   };
 
-  pond = buildFromGitHub {
+  pond = let isx86_64 = stdenv.lib.any (n: n == stdenv.system) stdenv.lib.platforms.x86_64; in buildFromGitHub {
     rev = "bce6e0dc61803c23699c749e29a83f81da3c41b2";
     owner = "agl";
     repo = "pond";
     sha256 = "1dmgbg4ak3jkbgmxh0lr4hga1nl623mh7pvsgby1rxl4ivbzwkh4";
 
-    buildInputs = [ net crypto protobuf ed25519 pkgs.trousers pkgs.dclxvi ];
+    buildInputs = [ net crypto protobuf ed25519 pkgs.trousers ]
+      ++ stdenv.lib.optional isx86_64 pkgs.dclxvi;
     buildFlags = "-tags nogui";
-    excludedPackages = "appengine";
+    excludedPackages = "\\(appengine\\|bn256cgo\\)";
+    postPatch = stdenv.lib.optionalString isx86_64 ''
+      grep -r 'bn256' | awk -F: '{print $1}' | xargs sed -i \
+        -e "s,golang.org/x/crypto/bn256,github.com/agl/pond/bn256cgo,g" \
+        -e "s,bn256\.,bn256cgo.,g"
+    '';
   };
 
   pongo2 = buildFromGitHub {