From 643469a17cac53d4989165a34e3266962d1ad6b0 Mon Sep 17 00:00:00 2001
From: Jack Nagel <jacknagel@gmail.com>
Date: Thu, 31 Oct 2013 14:20:29 -0500
Subject: [PATCH] sh: only activate X11 if it's installed

Fixes Homebrew/homebrew#23835.
---
 Library/Homebrew/cmd/sh.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Library/Homebrew/cmd/sh.rb b/Library/Homebrew/cmd/sh.rb
index 82fcc968d8..d05af5bfd0 100644
--- a/Library/Homebrew/cmd/sh.rb
+++ b/Library/Homebrew/cmd/sh.rb
@@ -6,7 +6,7 @@ module Homebrew extend self
     ENV.activate_extensions!
 
     if superenv?
-      ENV.x11 = true
+      ENV.x11 = MacOS::X11.installed?
       ENV.deps = Formula.installed.select{|f| f.keg_only? and f.opt_prefix.directory? }.map(&:name)
     end
     ENV.setup_build_environment