First Installation Issues

[ipTresolavy]

As this workplace begins to spread and be installed in different environments, many different issues may arise. This post briefly documents the first issues encountered while installing and setting the skyrats-workplace up and how they were solved. The reason behind some of the following issues is still not fully known, so any information contributed will be helpful

By order of appearance:

1. Issues with java packages during bash skyrats.sh execution
2. Issues while building workspace (catkin build)
3. Issues when trying to run the simulation (roslaunch px4 mavros_posix_sitl.launch)

1. Issues with java packages during bash skyrats.sh execution

In my machine (Ubuntu 20.04.3 LTS), skyrats.sh was not able to install some java packages, such as oracle-java17-installer_17.0.1-1~linuxuprising5_amd64.deb. This may be related to the fact that I had already previously installed java via the package manager apt. In any case, this error seemingly did not impact the rest of the installation process, which could also be explained by the same reasoning.

2. Issues while building workspace (catkin build)

Two main issues arose during the catkin build process:

• Absence of ROS packages
• CMake flags making it impossible to build px4

For the former, the solution was straightforward: just installing the packages not found by the system solved the problem. In my case, I had to run the following:

sudo apt-get install ros-<ROS_DISTRO>-angles
sudo apt-get install ros-<ROS_DISTRO>-cv-bridge
sudo apt-get install ros-<ROS_DISTRO>-control-toolbox

As of today (2021-11-04), this workplace comes with the noetic distribution of ROS, so I replaced <ROS_DISTRO> by noetic when running the command. You may need to change it into your ROS distribution.

For the latter issue, my gcc compiler was not allowing a logical 'and' of equal expressions, which happened inside px4's package source code, and, therefore, prevented my workspace from being built. This was being triggered by the -Werror=logical-op flag. Turns out different gcc versions behave differently with regards to the flag. After simply switching from gcc-11 to gcc-9, the problem was solved.

3. Issues when trying to run the simulation (roslaunch px4 mavros_posix_sitl.launch)

Finally, after running make px4_sitl gazebo inside the px4_firmware directory, the roslaunch px4 mavros_posix_sitl.launch would output the following:

Even though gazebo was already installed, it could not be found by the launch command. The solution was to install some gazebo-ros packages via the package manager, apt, in my case:

sudo apt-get install ros-<ROS_DISTRO>-gazebo-ros ros-<ROS_DISTRO>-gazebo-ros-pkgs ros-<ROS_DISTRO>-gazebo-ros-control

That was it. Any elucidation on the topics mentioned here will be helpful, so feel free to add a comment below :).