Wednesday, March 04, 2015

The Art of Bugging: or Where Do Bugs Come From

Author's Note: When I first published this list in 1981, it was widely distributed by fans. Then for while, it disappeared. Every year, I received a request or three for a copy, but by 2000, I'd lost the original. This month, when closing up our cabin in the woods, it turned up in the back of a file cabinet. Inasmuch as I've been writing recently about testing (as in Perfect Software), and as it seems still up-to-date and relevant, I decided to republish it here for the grandchildren of the original readers.

Not so long ago, it wasn't considered in good taste to speak of errors in computer systems, but fashions change. Today articles and books on software errors are out-numbered only by those on sex, cooking, and astrology. But fashion still rules. Everybody talks about debugging—how to remove errors—but it's still of questionable taste to speak of how the bugs get there in the first place. In many ways, the word "debugging" has injured our profession.

"Bug" sounds like something that crawled in under the woodwork or flew through a momentary opening of the screen door. Misled by this terminology, people have shied away from the concept of software errors as things people do, and which, therefore, people might learn not to do.

In this column, I'd like to shift the focus from debugging—the removal of bugs—to various forms of putting them in the software  to begin with. For ease of reference, I'll simply list the various types of bugging alphabetically.

Be-bugging is the intentional putting of bugs in software for purposes of measuring the effectiveness of debugging efforts. By counting the percentage of intentional bugs that were found in testing, we get an estimate of the number of unintentional bugs that might still be remaining. Hopefully,  we remember to remove all the be-bugs when we're finished with our measurements.

Fee-bugging is the insertion of bugs by experts you've paid high fees to work on your system. Contract programmers are very skilled at fee-bugging, especially if they're treated like day laborers on a worm farm.

Gee-bugging is grafting of bugs into a program as part of a piece  of "gee-whiz" coding—fancy frills that are there to impress the maintenance programmers rather than meet the specifications.

Knee-bugging is thrusting bugs into a program when you're in too much of a hurry to bend your knee and sit down to think about what you're doing. We have a motto—"Never debug standing up." We could well extend that motto to bugging: "Never bug standing up."

Me-bugging may involve numerous forms of bug installation," for it refers to the method by which they are protected from assault. The programmer regards any attempt to question the correctness of the code as an assault on his or her value as a human being. Those who practice "egoless programming" are seldom guilty of me-bugging.

Pea-bugging can be understood by reference to the story of The Princess and the Pea. The princess showed her true royalty by being able to feel a pea through a hundred mattresses, illustrating that no bug is too small to be noticed by computers or other royalty. The pea-bugger,
however, pops in little bugs with the thought, "Oh nobody will ever notice this tiny glitch."

Pee-bugging is the rushing in of bugs when the programmer is impatient to attend to other matters, not necessarily the call of nature. The pee-bugger is the one who is always heard to contribute: "Lets just get this part coded up so we can get on to more important matters."

Plea-bugging is the legalistic method of forcing bugs into software. The plea-bugger can argue anyone out of any negative feeling for a piece of code, and is especially dangerous when walking through code, leading the committee around by its collective nose.

Pre-bugging is the art of insinuating bugs into programs before any code is written, as in the specification or design stages. We often hear the pre-bugger saying, "Oh, that's clear enough for the coders. Any moron could understand what we mean."

Re-bugging is the practice of re-introducing bugs that were already removed, or failing to remove bugs that were found and supposedly removed. Re-bugging is especially prevalent in on-line work, and some on-line programmers have been known to collapse from malnutrition when caught in an endless loop of debugging and rebugging a related pair of bugs.

Sea-bugging is named for the state of mind in which it is done—"all at sea." The typical sea-bug splashes in when everyone is making waves and shouting, "We've got to do something!" That something is invariably a bug—unless it's two bugs.

See-bugging is the implantation of bugs that "everyone can see" are correct. See-bugging is done in a state of mass hypnosis, often when too many susceptible minds are pooled on the same team or project. This unhealthy state prevails when management values harmony over quality, thus eliminating anyone who might make waves. Of course, too many wave makers leads to sea-bugging, so programming teams have to be constituted as a compromise between harmony and healthy discord.

S/he-bugging is done all the time, though nobody likes to talk about it. S/he-bugs have a way of infusing your code when your mind is on sex, or similar topics. Because sex is a topic unique unto itself, all s/he bugs originate by what might be referred to as sexual reproduction. That's why this is such a populous class of bugs.

Tea-bugging is the introduction of bugs when problems are solved during tea and coffee break conversations and then not checked before passing directly into the code.

The-bugging (pronounced thee-bugging) is crowding multiple bugs into a program under the "one-program-one bug" fallacy. The addicted the-bugger can invariably be heard ejaculating: "I've just found the bug in my program."

We-bugging is the ordination of bugs by majority rule. When someone doubts the efficacy of a piece of code, as in a review, the majority votes down this disturbing element, for how can three out of five programmers be wrong? Thus are born we-bugs.

Whee-bugging is a symptom of boredom, and frequently arises when Agile programming and other bug-prevention schemes have become well-established. Programmers reminisce about "the good old days," when programmers proved their machismo by writing code in which nobody could find bugs. One thing leads to another, and eventually someone says, "Let's do something exciting in this piece of code—wheeeeeel"

Ye-bugging is a mysterious process by which bugs appear in code touched by too many hands. Nobody knows much about ye-bugging because every time you ask how some bug got into the code, every programmer claims somebody else did it.

Z-bugging is the programmer's abbreviation for zap-bugging. The zap-bugger is in such a hurry that it's unthinkable to use three letters when one will do. Similarly, it's unthinkable to submit to any time-wasting controls on changes to working code, so the Z-bugger rams bugs into
the operating system with a special program called ZAP, or SUPERZAP. Although Z-bugs are comparatively rare, they are frequently seen because they always affect large numbers of people. There's a saying among programmers, perhaps sarcastic, "All the world loves a Z-bugger."

So there they are, in all their glory, nineteen ways that people put errors in programs. There are others. I've heard rumors of tree-bugs, spree-bugs, agree-bugs, tee-hee-hee-bugs. and fiddle-dee-dee bugs. I'm tracking down reports of the pernicious oh-promise-me-bug. Entymologists estimate that only one-tenth of all the world's insect species have been discovered and classified, so we can look forward to increasing this bugging list as our research continues. Too bad, for we seem to have enough already.

Note added in 2015: Yes, we had enough, but many have been added. If you know of a bug we didn't list here, I invite you to submit a comment about it.

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