A hands-on tutorial for using the GNU Project Debugger: 
If you’re a programmer and you want to put a certain functionality in your software, you start by thinking of ways to implement it—such as writing a method, defining a class, or creating new data types. Then you write the implementation in a language that the compiler or interpreter can understand. But what if the compiler or interpreter does not understand the instructions as you had them in mind, even though you’re sure you did everything right? What if the software works fine most of the time but causes bugs in certain circumstances?
read more: Opensource.com hANSIc99
Supporting Open Source.
Have you tried: Sailing in Africa ?