I'm an undergrad TA for an introductory programming course, and I believe it is one of the most important skills that is not taught in the actual syllabus. Most every student runs into road blocks at some time. When I work with them, I try to work through a process of debugging. Even for me, it took me a number of years to have a rigorous concept of what debugging entails, and often still takes me some time before I decide to attack the issue in a systematic way, even if beginning the debugging process formally would be a much more efficient use of my time.