Read the Tea Leaves Software and other dark arts, by Nolan Lawson

At every development team I’ve worked with, we’ve used Jenkins to notify us when the build broke. (Or Hudson, as it was called before Kohsuke Kawaguchi nailed a proclamation to the church wall.) Everyone on the team would receive an email when a unit test failed, or when someone forgot to commit a file, or when some other random blunder occurred.

Jenkins is really invaluable for finding problems early. And of course, publicly shaming the guilty party is always a great source of fun. The Continuous Integration Game plugin is even better for this.

But at my current employer, my colleague Alexandre Masselot had a singularly brilliant idea: instead of just firing off an email, why not add a visual cue as well? So he set up a physical flag system, attached to a USB servo device, with a cron script that would raise the flag whenever a Jenkins build failed. It looked like this:

Everyone on the dev team loved it. If the flag was raised when we walked into the office in the morning, the first question at the scrum meeting would be, “Who broke the build?” And as soon as the flag started to rise, you could hear the servo cranking, and the guilty developer would announce, “That was me!” A good time was had by all.

But could we do better?

The developers on the far side of the room couldn’t always hear the cranking sound, so they often didn’t notice when the flag was raised. So we decided to add an audio cue as well. Every time the build was broken, the machine would play the Star Wars “Imperial March” (aka Darth Vader’s theme), using the Unix beep command, since this particular machine had no speakers. It sounded like this:

And every time the build was fixed, it would play the main theme of Star Wars, to celebrate the joyous occasion:

This solved the immediate problem. The cacophonous beeping that signaled a build failure could be heard on the far side of the room. And beyond, where even the non-devs in the office could enjoy the sweet sound of pure geekiness.

But could we do better?

Whenever Darth Vader thundered his beeping fanfare, all the developers would immediately stop and check Jenkins to see which component broke. We didn’t have a quick way to know “whodunnit.”

So we added a new feature: an Android phone attached via USB, plus a simple text-to-speech app that would announce the name of the guilty party and the component that he or she broke.

The end result is that whenever the build is broken: the following events occur:

1. The flag goes up
2. The dreaded “Imperial March” sounds
3. A robotic voice says “So-and-so broke the build, in the project such-and-such.”

The final system looks like this:

Then, when the build is back to normal, the system announces who fixed it, and all is forgiven:

So nowadays, whenever we start to hear the infernal beeping from our Jenkins machine, everyone takes off their headphones and patiently waits to hear who broke the build. Possibly with some apologies/excuses/complaints from the accused individual. (“It’s because the downstream project built before I was ready!”)

In any case, it makes our office much more melodious and much more fun. And luckily, the nearest non-dev is a Star Wars geek, so she doesn’t mind our antics.

Do it yourself

If you’d like to recreate our setup, it will only cost you about 40 bucks and a little bit of development time. You’ll need:

1. A Yocto-Servo device ($25)
2. A micro USB cable to connect it ($6)
3. A micro servo to work the flag ($8)
4. The flag itself (we used a Canadian flag, because it’s what I had, eh)
5. The cron script to call Jenkins and raise the alarm
6. The SimpleTalker app, if you have an Android device available. We use an old HTC Magic.

Bonus features

We also experimented with a few other features. If you use this excellent Python script to convert MIDI files into beep format, for instance, you can find any MIDI you like and make it into euphonious beep music. Here’s what this Super Mario Bros. theme from VGMusic.com sounds like:

And you could use the Mario “game over” theme for a build failure:

Alternatively, the Android app I wrote supports specifying an MP3 file on the device’s storage, in addition to the text-to-speech. Maybe each of your developers prefers a personalized “failure” and “success” theme? The sky’s the limit.

And if the beeping sound isn’t annoying enough, I will humbly point out that Yoctopuce also offers USB modules to operate an emergency rotating light. I take no responsibility for the mental health of your office-mates if you actually install such a device.

Summary

Programming is fun. And in our office, we’ve found that turning programming into an audiovisual experience makes it even more fun. I hope you’ll get a kick out of the code we’ve written, and that your boss won’t think it’s a waste of time. (Ours didn’t, although she keeps the door to her office firmly closed now.)