Probably 10 times a semester, a student taking one of my courses sends me a mail like this:
Dr. Regehr I have this bug I’ve been working on for a long time, I’ve tried everything, I’m going to miss the deadline…
and then 15 minutes later, I get another email:
Nevermind I figured it out.
Is it a coincidence that students mail me just as they’re about to solve a difficult debugging problem? It is not. Rather, they have previously failed to explain the bug clearly to themselves. By explaining it to me in the email, they explain it to themselves and that is all it takes to figure it out. Seriously, I hardly even need to read this stuff.
Since I can solve so many problems with so little effort, I’m thinking it’s time to scale this up. Perhaps I’ll create a web site “Mail a Professor” where people can ask for advice about their worst debugging problems. Nobody will read the mails, but people will get a nice randomized response saying things like “Your makefile contains a suspicious dependency” or “Please explain step two in more detail, I don’t yet understand what’s going on” or “Have you tried the latest version of Valgrind?”