Don't send, just call the method directly

Library/Homebrew/cmd/cleanup.rb

@@ -114,7 +114,7 @@ class Formula
         select{ |ff| ff.deps.map{ |d| d.to_s }.include? name }.
         map{ |ff| ff.rack.subdirs rescue [] }.
         flatten.
-        map{ |keg_path| Tab.for_keg(keg_path).send("HEAD") }.
+        map{ |keg_path| Tab.for_keg(keg_path).HEAD }.
         include? nil
     end
   end

Library/Homebrew/tab.rb

@@ -124,7 +124,7 @@ class Tab < OpenStruct
       :poured_from_bottle => poured_from_bottle,
       :tapped_from => tapped_from,
       :time => time,
-      :HEAD => send("HEAD"),
+      :HEAD => self.HEAD,
       :stdlib => (stdlib.to_s if stdlib),
       :compiler => (compiler.to_s if compiler)})
   end