From e2212aee7ef3f7646f79035e91f67d5bd86afe9e Mon Sep 17 00:00:00 2001
From: Mario Rodas <marsam@users.noreply.github.com>
Date: Tue, 10 Mar 2020 04:20:00 -0500
Subject: [PATCH] ocamlPackages.eigen: fix build on darwin

---
 pkgs/development/ocaml-modules/eigen/default.nix | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/ocaml-modules/eigen/default.nix b/pkgs/development/ocaml-modules/eigen/default.nix
index 8f26213c23ae..3922b5cfec75 100644
--- a/pkgs/development/ocaml-modules/eigen/default.nix
+++ b/pkgs/development/ocaml-modules/eigen/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, buildDune2Package, fetchFromGitHub, ctypes }:
+{ stdenv, buildDune2Package, fetchFromGitHub, ctypes, libcxx }:
 
 buildDune2Package rec {
   pname = "eigen";
@@ -13,6 +13,8 @@ buildDune2Package rec {
 
   minimumOCamlVersion = "4.02";
 
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.isDarwin "-I${libcxx}/include/c++/v1";
+
   propagatedBuildInputs = [ ctypes ];
 
   meta = with stdenv.lib; {