--- nokogiri-1.6.6.4/./lib/nokogiri/version.rb.nowarn	2015-11-20 05:50:37.000000000 +0900
+++ nokogiri-1.6.6.4/./lib/nokogiri/version.rb	2015-12-11 14:32:04.151973080 +0900
@@ -34,6 +34,7 @@
     end
 
     def warnings
+      return []
       return [] unless libxml2?
 
       if compiled_parser_version != loaded_parser_version