I’ve had to debug some interesting problems in my time. These are some of the ones I can remember. I’ll continue adding to these as I think of them.
The Disappearing Return Value
I hit this at the very beginning of my time working on HHVM. While working on an unrelated task, I encountered this bizarre symptom, which took me a while to even notice, and then sent me down a very fun rabbit hole to debug.
The SoftBank Timeout
An adventure into the world of Japanese cell phones in 2012, during my time at Facebook.
The Response to the Wrong Request
I encountered this in my work at Segovia. It appeared quite rarely, and everyone’s best efforts at debugging turned up nothing. For all I know it’s still happening. When I left the company, I wrote in the internal bug tracker that if anyone ever solves this mystery, they are to contact me and tell me what the hell was going on, or else I’ll be haunted forever.
I write this story with the faint hope that someone will read it, recognize this problem, and finally give me some closure.