A bug’s life: The tale of debugging in CS 106A

I

During the furious early-morning typings on a dim computer screen, a bug is born within a nest of brackets. Jumbled inconspicuously between various foggy lines of late night code, the bug sleeps innocently in the assignment of a novice computer science student.

As the bug lies in hibernation, its surroundings continue to grow, line by line.

Possibly, a few new bugs are born in the surrounding Java text. Possibly, our bug is the last of its kind in the program – an endangered insect species.

II

As the student’s typing stutters to a halt and a final few lines conclude the program, the student clicks a button to run it.

Sweeping through lines one, two, three – the run path is smooth. However, as the program approaches our unsuspecting bug, it stumbles. Abruptly roused from its dormancy, the bug frantically waves a warning flag. The program’s sweeping path is truncated. The call of alarm is heard. A pop-up error bar appears on the student’s screen.

General sadness ensues.

III

The doleful student fumbles for insecticide and begins scouring through the code, but his sleep-weary eyes are blind to our bug’s furtive waving.

Each time the program runs and crashes, our bug beckons for the students attention, but the frenzied motions of his tiny appendages are lost to the undergrowth of semicolons, parentheses and text.

The night is late, and the student’s prospects look bleak. It is time to apply for help.

IV

After a long queue of fellow students struck by similar bug infestations, the student is finally able to consult the CS 106 LaIR section leaders, a group of experienced pest inspectors. Here, the plaintive gesturing of a distressed bug is usually identified.

In the rare case that the bug remains overlooked, the program is quarantined and passed to a Slack group of all current section leaders and the head TA, the head pest vanquisher. With their collective knowledge in computer science entomology, even the best-camouflaged bug is recognized from the foliage of text.

V

Having successfully caught the bug, the student swiftly removes it. The death of the bug is duly noted as – hopefully – the extinction of its kind.

Contact Irene Han at irenehan ‘at’ stanford.edu.