Debugging

"Even perfect program verification can only establish that a program meets its specification. […] Much of the essence of building a program is in fact the debugging of the specification."

"Much to the surprise of the builders of the first digital computers, programs written for them usually did not work."

"bug, n: An elusive creature living in a program that makes it incorrect. The activity of "debugging", or removing bugs from a program, ends when people get tired of doing it, not when the bugs are removed."

"If debugging is the process of removing bugs, then programming must be the process of putting them in."

"Testing can only prove the presence of bugs, not their absence."

"silver bullet (SIL-vuhr BOOL-it) noun: A quick solution to a thorny problem. [From the belief that werewolves could be killed when shot with silver bullets.] "Writing code, he (Stuart Feldman) explains, is like writing poetry: every word, each placement counts. Except that software is harder, because digital poems can have millions of lines which are all somehow interconnected. Try fixing programming errors, known as bugs, and you often introduce new ones. So far, he laments, nobody has found a silver bullet to kill the beast of complexity.""

"From then on, when anything went wrong with a computer, we said it had bugs in it."

"The most effective debugging tool is still careful thought, coupled with judiciously placed print statements."

"Everyone knows that debugging is twice as hard as writing a program in the first place. So if you're as clever as you can be when you write it, how will you ever debug it?"

"Beware of bugs in the above code; I have only proved it correct, not tried it."

"A documented bug is not a bug; it is a feature."

"Given enough eyeballs, all bugs are shallow."

"As soon as we started programming, we found to our surprise that it wasn't as easy to get programs right as we had thought. Debugging had to be discovered. I can remember the exact instant when I realized that a large part of my life from then on was going to be spent in finding mistakes in my own programs."

"The last bug isn't fixed until the last user is dead."