How do we go about reporting this kind of bugs, when the interpreter
crashes on you, with those strange bugs which come in/go away as you
move comments around.

$ ruby Captive.rb
: [BUG] unknown node type 0
ruby 1.8.1 (2004-03-31) [i586-linux-gnu]

Aborted

I have little chance of making a short example with the bug as it is
highly dependant on the layout of the script.

I moved from 1.8.1 stable to a stable-snapshot for exactly the same type
of bug. The latest stable-snapshot (April 5th 2004) doesn't compile
correctly (the test fails with: not ok float 10 --
/home/development/RPM/BUILD/ruby-1.8.1/sample/test.rb:1183:in
`nan_test'). I cannot retreat any further into bleading edge stable
releases!

What can I do to help correct this bug?

Guillaume.