Heisenbug

2 definitions found

From Jargon File (4.3.1, 29 Jun 2001) [jargon]:

  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}.
  
  

From The Free On-line Dictionary of Computing (27 SEP 03) [foldoc]:

  heisenbug
       
           /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)