"Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." — Brian Kernighan (co-inventor of the C programming language).
You shouldn't take it literally of course, but there is a grain of true to both parts: debugging is harder than programming and also, if you write your code too cleverly, you'll have trouble debugging it. One lesson to take away is that you should write clear and simple code that is easy to understand and troubleshoot when something goes wrong.
Another way to look at it is that when something does go wrong you want all the help you can get to fix it. One of the main the Agile practices is pair programming, where two programmers collaborate in front of a single screen and keyboard — probably the least popular in the Agile arsenal. However, pair debugging is taking all the goodness of pair programming into the debugging experience. You don't have to feel you're all alone against the inscrutable code. Your partner will help you through tight spots and see things you don't notice. Sometimes just explaining the problem to your partner may shed a light on what's going on. I've had a very good track record where the combined efforts of the pair found the root cause after a single programmer was stuck for a long time banging their head against the metaphorical wall.
My recommendation would be that when you face a difficult problem, try to solve it on your own, but as soon as you run out of ideas or feel overwhelmed call in the cavalry. Describe what you know and what you have done so far and you'll be surprised that often that alone will get you unstuck. If not, your partner will probably have some ideas regarding how to move forward. Happy pair debugging.
Agile programming, agile development, agile practices, agile methodologies, pair programming