find_constant.rb

require 'stringio'

def find_constant const
  return nil unless Object.const_defined? const

  value = Object.const_get const

  $stderr = StringIO.new
  Object.const_set const, nil

  $stderr.rewind
  ret = $stderr.read.lines.last.split(': ').first
  $stderr = STDERR

  v, $VERBOSE = $VERBOSE, nil
  Object.const_set const, value
  $VERBOSE = v

  ret
end