[sytelus]

This is actually well written article by a CS professor and cited with experiences of few very productive programmers. Especially Linus's no bar holds post on this topic is worth reading:

https://lwn.net/2000/0914/a/lt-debugger.php3

Many people say not using debugger is other side of the pendulum but perhaps it is not. You want to have assertions/prints in your program at critical junctions. That should be able to explain the behavior of the program you are seeing. If it doesn't then you probably have missed some critical junctions OR don't really understand your own code. There is actually a third possibility where you will need debugger. This is the case when compiler/programming language/standard libraries itself has bug. Instead of more time consuming binary search for where you first get unexpected output, debugger might be better option.