January 29, 2007

Fejlkilder I

"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."
-- fra The Jargon File

"Debugging is a black art. Preaching specification from an ivory tower is fine but applying theory to improve the state of the art inthe real world is not a bad thing."
-- fra Daily ETAPS

"Problems that can arise from accepting any bug report as a command to fix include:

  • Your reputation can suffer because it appears that you can’t fix some of these “unfixable” bugs, especially the unreplicable ones.

  • Your reputation can suffer because you are spending too much time developing new features under the guise of bug fixing, and so you are perceived as having a buggy system rather than a full-
  • featured one.
  • Your bug tracking system gets cluttered with lots of unreplicable bugs, which never get fixed since they can’t be replicated."

-- fra Shouting Distance

"Skepticism and Cynicism may not seem like opposites, but in the world of debugging, they often are. As discussed yesterday, the Cynical Debugger says “I believe that things can and will go wrong, and I want to plan for that.” Balancing that attitutde, the Skeptical Debugger says “I don’t believe that bug report” and “There’s probably a much simpler explanation”. An expert debugger knows how to manage the tension between wanting to accept the crazy things that happen to an application in the wild, and wanting to dismiss bad or highly improbable data."
-- fra Shouting Distance

Posted by Ishmael at 10:11 PM