gistfile1.rb

require 'nokogiri'

xml = <<END
<foo xmlns="http://example.com">
  <bar xmlns:n1="http://bar.com">
    <baz xmlns:n2="http://baz.com">
    </baz>
  </bar>
</foo>
END

loop do
  doc = Nokogiri.XML(xml)
  list = doc.xpath('//namespace::n1')
  ns = (doc%'bar').namespace # this plus previous triggers segv
#  list.push(ns) # after fixing segv, fix this memleak!
end