Re: Heisenbugs (was: Filing bugs with upstream)

[Petter Reinholdtsen <pere@hungry.com>]

[Frank Küster]
> I probably understand what you mean, but what exactly is a Heisenbug?
> What's the complementary quantity to buggyness that gives a product
> smaller than \hbar?

<URL:http://www.jargon.net/jargonfile/h/heisenbug.html>:

  heisenbug /hi:'zen-buhg/ /n./ [from Heisenberg's Uncertainty
    Principle in quantum physics] A bug that disappears or alters its
    behavior when one attempts to probe or isolate it. (This usage is
    not even particularly fanciful; the use of a debugger sometimes
    alters a program's operating environment significantly enough that
    buggy code, such as that which relies on the values of
    uninitialized memory, behaves quite differently.) Antonym of Bohr
    bug; see also mandelbug, schroedinbug. In C, nine out of ten
    heisenbugs result from uninitialized auto variables, fandango on
    core phenomena (esp. lossage related to corruption of the malloc
    arena) or errors that smash the stack.