Restore HOMEBREW_LOG functionality

Library/ENV/4.3/cc

@@ -21,6 +21,18 @@ def syspath
     %W{/usr /usr/local}
   end
 end
+def exec *args
+  path = File.expand_path('~/Library/Logs/Homebrew/cc.log')
+  open(path, 'a') do |f|
+    f.print '[', $0
+    f.print " -%s" % ENV['HOMEBREW_CCCFG'] if ENV['HOMEBREW_CCCFG']
+    f.print '] '
+    f.puts args.join(' ')
+    f.puts
+  end
+  Kernel.exec *args
+end if ENV['HOMEBREW_LOG']
+
 
 class Cmd
   def initialize path, args

Library/ENV/4.3/xcrun

@@ -4,8 +4,6 @@
 # But many build-systems expect it to work. This fixes that.
 # NOTE only works if the build-tool calls xcrun without a path prefixed!
 
-ENV['HOMEBREW_LOG'] = nil
-
 require "#{File.dirname __FILE__}/../libsuperenv"
 SUPERBIN = __FILE__.dirname.cleanpath.freeze
 

Library/ENV/libsuperenv.rb

@@ -25,20 +25,5 @@ class Array
   end
 end
 
-module Kernel extend self
-  alias :_exec :exec
-  def exec *args
-    path = File.expand_path('~/Library/Logs/Homebrew/cc.log')
-    open(path, 'a') do |f|
-      f.print '[', $0
-      f.print " -%s" % ENV['HOMEBREW_CCCFG'] if ENV['HOMEBREW_CCCFG']
-      f.print '] '
-      f.puts args.join(' ')
-      f.puts
-    end
-    _exec *args
-  end
-end if ENV['HOMEBREW_LOG']
-
 $brewfix = "#{__FILE__}/../../../".cleanpath.freeze
 $sdkroot = ENV['HOMEBREW_SDKROOT'].freeze