From: Nobuyoshi Nakada Date: 2011-06-11T19:49:14+09:00 Subject: [ruby-core:37027] [Ruby 1.9 - Bug #4859][Rejected] Debug output in 1.8 vs 1.9 Issue #4859 has been updated by Nobuyoshi Nakada. Status changed from Open to Rejected Now Array#flatten tries to expand elements by to_ary, that is it's a spec change. ---------------------------------------- Bug #4859: Debug output in 1.8 vs 1.9 http://redmine.ruby-lang.org/issues/4859 Author: Aaron Patterson Status: Rejected Priority: Normal Assignee: Category: Target version: ruby -v: ruby 1.9.2p136 (2010-12-25 revision 30365) [x86_64-darwin10.7.0] This code emits warnings in debug mode in 1.9 but does not in 1.8: $-d = true class Foo def method_missing(method, *args, &block) super end end [[Foo.new]].flatten In 1.8, there is no output, but in 1.9 it says: Exception `NoMethodError' at warn.rb:5 - undefined method `to_ary' for # -- http://redmine.ruby-lang.org