DidYouMean::Correctable can cause NoMethodErrors to become undumpable

[jessebs]

The following code fails on Marshal.dump because the receiver set in DidYouMean::MethodNameChecker is not dumpable (it's an IO object)

def test_dump_exception
  File.open('/tmp/file').sizee
rescue NoMethodError => e
  e.to_s
  puts 'before'
  Marshal.dump(e)
  puts 'after'
end

If I remove the e.to_s line, the dump works fine. This is because MethodNameChecker is instantiated as part of Correctable.to_s, which sets the receiver.

One proposal is to remove the receiver while dumping. A better solution is to do whatever ruby does with the receiver while dumping NameError (the parent of NoMethodError)