heisenbug

2 definitions found

heisenbug - Free On-line Dictionary of Computing (26 May 2007) :

  heisenbug
  
     <jargon> /hi:'zen-buhg/ (From Heisenberg's Uncertainty
     Principle in quantum physics) A bug that disappears or alters
     its behaviour 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 uninitialised memory, behaves quite
     differently.)
  
     In C, nine out of ten heisenbugs result from uninitialised
     auto variables, fandango on core phenomena (especially
     lossage related to corruption of the malloc arena) or errors
     that smash the stack.
  
     Opposite: Bohr bug.  See also mandelbug, schroedinbug.
  
     [Jargon File]
  
     (1995-02-28)
  

heisenbug - Jargon File (4.4.4, 14 Aug 2003) :

  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.