From ecdc1ecd9c8d502ad3ef9cfe8d48645319120bac Mon Sep 17 00:00:00 2001
From: Mario Rodas <marsam@users.noreply.github.com>
Date: Fri, 13 Sep 2019 22:00:00 -0500
Subject: [PATCH] chez: fix build on darwin

---
 pkgs/development/compilers/chez/default.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/development/compilers/chez/default.nix b/pkgs/development/compilers/chez/default.nix
index 12d68f0265c..a0fc30c8586 100644
--- a/pkgs/development/compilers/chez/default.nix
+++ b/pkgs/development/compilers/chez/default.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
-  NIX_CFLAGS_COMPILE = "-Wno-error=format-truncation";
+  NIX_CFLAGS_COMPILE = stdenv.lib.optional stdenv.cc.isGNU "-Wno-error=format-truncation";
 
   /*
   ** We patch out a very annoying 'feature' in ./configure, which