The following training video shows one how to use the debugger named GDB within the OpenFOAM® framework. As a pre-requisite, one has to compile the code with the corresponding compiler flags which enable the usage of a debugger. Note, compiling the code with debugging flags will result in much longer execution time. Tobias recorded this video during the year 2016 and is based on the OpenFOAM® version 4. However, debugging does not depend on the version you are using and is a tool for a more fundamental analysis of your underlying c++ code. The comprehensive video can be an addition to the »Introduction and new Solver« screencast training video series.