rdoc aborting?

Hi,

I just had a strange behavior of rdoc. I tried to run rdoc on a ruby
code file, but found that only the first class got documented. I
stripped the example down to


class Config

  def update
    ist <<l
  end

end

class Test
end




rdoc (debian unstable) generates documention only for the first
class. But when putting a space between << and l  or removing the
line, it works. 

Any reason why rdoc aborts without error message?

regards
Hadmut