Issue #8357 has been reported by skwosh (Alex Goldsmith).

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Bug #8357: Module#prepend breaks comparison operator
https://bugs.ruby-lang.org/issues/8357

Author: skwosh (Alex Goldsmith)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: ruby 2.1.0dev (2013-05-02) [x86_64-darwin12.3.0]
Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN


Array < Enumerable # => true
Enumerable.send :prepend, Module.new
Array < Enumerable # => nil
Array.ancestors.include? Enumerable # => true

Same thing happens in 2.0.0-p0.

Possibly similar to what's happening in: http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/53106




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