Terminator exorcist
A Terminator exorcizing my code

In 2007 I started my career as a web developer in a web agency. One day one of my colleague had a problem that seemed to have been bothering her for a pretty long time. I told her to tell me about the problem but before she finished the explanation : bang! she found the solution just as she was trying to describe her problem to me.

We tried this several times after that, and every time it worked. As there was some kind of magic in all this, I called it Exorcism. That was a so efficient way to find solutions that I have been using it up until now.

The current rules for a good exorcism are as follows:

  1. A developer has been stuck with a problem for a while. He read and reread again the  whole thing without finding what was wrong with the code
  2. He calls for an exorcism
  3. Another member of the team grabs his scepter of exorcism (a thirty-centimeter ruler) and gets closer to the developer in trouble
  4. The developer explains the problem to the exorcist with much details while the exorcist pretends to listen (actually listening is optional)
  5. Suddenly the developer stops talking, much probably in the middle of a sentence : he has just found about the cause of his problem
  6. The exorcist brandishes his scepter in front of his exorcised teammate, letting a mystical sound flow out of his mouth (something like “haaaaaaaaaaaa…”)

I have long thought that I had invented this debugging methodology, until I recently discovered that many people do the exact same thing. This is actually a pretty common practice which have many different names. Some people do not even call another member of the team but explain their problems to a toy, a wall, a mirror, a stuffed duck, IRC or a text file, etc. So do not hesitate to implement it with your team, as this is both a fun and efficient way to debug some tricky problem.

As a concluding anecdote, here is the best exorcism I have ever practiced : One of my colleague was struggling against some code. He did not understand why some loop was not doing what he wanted it to do. He had already placed several watches and breakpoints but still could not figure out what was happening…so he called for a exorcism. After a brief explanation he said : “So the only way for the loop to behave like this is that there is a break right here!” You know exactly how it ended…

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