Debugging applications

Compile the package you need

Avoid running catkin build without specifying a package since this builds the entire workspace which takes a long time. You can specify individual packages simply by adding their names:

catkin build maplab

Build single packages efficiently

If you only changed a single package you can also restrict the build process to this single package:

catkin build maplab --no-deps

Even more efficient is invoking make -j8 in the build folder of the package

cd ~/maplab_ws/build/maplab && make -j8

Compile in Release mode

Most packages are not built in Release mode. To build packages in Release mode:

catkin build maplab --cmake-args -DCMAKE_BUILD_TYPE=Release

To set this as the default behavior in your current catkin profile:

catkin config --cmake-args -DCMAKE_BUILD_TYPE=Release

Change individual packages to Debug mode

If you want to debug a program it makes sense to switch the package that the error is contained in to Debug mode.

cd ~/catkin_ws/build/maplab
ccmake .

If ccmake is not installed on your system, you have to install it using:

sudo apt-get install cmake-curses-gui

If ccmake is there, you will now see a window similar to this:

 BUILD_SHARED_LIBS                ON
 CATKIN_DEVEL_PREFIX              /Users/slynen/catkin_ws/devel
 CMAKE_BUILD_TYPE                 Release
 CMAKE_INSTALL_PREFIX             /Users/slynen/catkin_ws/install

Navigate to the line which says CMAKE_BUILD_TYPE using the cursor keys and press Enter. Now replace Debug with Release. Press c to configure, followed by g to generate. (you might now press e to hide warnings.). Finally press q to quit. Now make the package by invoking:

cd ~/maplab_ws/build/maplab && make -j8

HINT: Don’t forget to switch back to Release once you are done with debugging.

Run gdb with arguments

In order to run a process with arguments in gdb, the most efficient way is to use:

gdb --ex run --args ~/devel/lib/maplab/maplab --use_external_memory=false

Where --use_external_memory=false is just an example flag.