I found one typo, and another instruction in the begining tutorials that would be nice if it got fixed.
The first typo is a 1 where a l is in a reference to a file name in the v4l2_camera. The program has a l but the instructions say 1, and the error message does not tell you anything related to that.
Second is in section "Developing Codlets in C++. Ping instructions tell you to run bazel from the ping directory but that does not work. I already learned the hard way only from workspace dir.