Silence more warnings

Library/Homebrew/extend/ENV/super.rb

@@ -28,6 +28,7 @@ module Superenv
     # done on the singleton class, because in MRI all ENV methods are defined
     # on its singleton class, precluding the use of extend.
     class << base
+      alias_method :"old_[]", :[]
       def [] key
         if has_key? key
           fetch(key)

Library/Homebrew/software_spec.rb

@@ -97,6 +97,7 @@ class Bottle < SoftwareSpec
     @revision = 0
     @prefix = '/usr/local'
     @cellar = '/usr/local/Cellar'
+    @root_url = nil
   end
 
   # Checksum methods in the DSL's bottle block optionally take