«stack level too deep» with puts in simple thread

[kreatix@…]

$ cat eval2.rb
#!/usr/local/bin/macruby

t = Thread.new do
  puts "hello"
end

t.join 

$ ./eval2.rb
./eval2.rb:5:in `puts': stack level too deep (SystemStackError)
	from ./eval2.rb:5:in `block in <main>'
$

[lsansonetti@…]

Fixed in r563/trunk.