From eb02996ed1033816d6205f6aece5ada8fab71c1d Mon Sep 17 00:00:00 2001
From: Michael Glass <me@mike.is>
Date: Wed, 23 Oct 2019 10:14:55 +0200
Subject: [PATCH] disable lto flag for darwin + nix

see https://github.com/sass/sassc-ruby/issues/148 for more context
---
 ext/extconf.rb | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/ext/extconf.rb b/ext/extconf.rb
index 08e067c1..f2a1507e 100644
--- a/ext/extconf.rb
+++ b/ext/extconf.rb
@@ -25,7 +25,12 @@
   $CXXFLAGS << ' -march=native -mtune=native'
 end
 
-if enable_config('lto', true)
+# darwin nix clang doesn't support lto
+# disable -lto flag for darwin + nix
+# see: https://github.com/sass/sassc-ruby/issues/148
+enable_lto_by_default = (Gem::Platform.local.os == "darwin" && !ENV['NIX_CC'].nil?)
+
+if enable_config('lto', enable_lto_by_default)
   $CFLAGS << ' -flto'
   $CXXFLAGS << ' -flto'
   $LDFLAGS << ' -flto'