ROS2 package demo 2 - repo design

Separate repos, use a .repos file like ros2 itsells

f and ros2_control Looking at major ros2 repos like ros2_control and ros2 itself, setup reads from a list of repos in a master repo. I want to organize in that matter.

The step Get ROS 2 code has these instructions:

mkdir -p ~/ros2_eloquent/src
cd ~/ros2_eloquent
wget https://raw.githubusercontent.com/ros2/ros2/eloquent/ros2.repos
vcs import src < ros2.repos

I want to duplicate this setup. Created three github repos: a master fqdemo, subrepos fqdemos-nodes and fqdemos-msgs. Repo list:

repositories:
  fqdemo-msgs:
    type: git
    url: https://github.com/rosdabbler/fqdemo-msgs.git
    version: main
  fqdemo-nodes:
    type: git
    url: https://github.com/rosdabbler/fqdemo-nodes.git
    version: main

I installed Install development tools and ROS tools

apt failed, no python-rosdep. apt list shows me it is called python3-rosdep. Fixed, reran install, this time it worked.

Now follow instructions:

mkdir -p fqdemo-ws/src
cd fqdemo-ws
wget https://raw.githubusercontent.com/rosdabbler/fqdemo/main/fqdemo.repos
vcs import src < fqdemo.repos

Yuck, vcs import wants me to enter github login. Nope, I had an error in repo name. Worked and pushed to https://github.com/rosdabbler/fqdemo. (also fixed in printout above)

If I look at ros2_control.repos I see that it is in a folder ros2_control/ros2_control with a bunch of other packages at the same level. ros_control.repos pulls in additional packages, sort of like subrepos under git. I think I will leave this as is for now.

I see that the checkout above was https:// I want to be able to modify, so the proper way is ssh. I see this vcs tool can creat the list automagically. I just need to clone repos first. Did that, ran `kent@ubutower:~/ros2_wses/fqdemo-ws$ vcs export src > fqdemos.repos and got for fqdemos.repos:

repositories:
  fqdemo-msgs:
    type: git
    url: git@github.com:rosdabbler/fqdemo-msgs.git
    version: main
  fqdemo-nodes:
    type: git
    url: git@github.com:rosdabbler/fqdemo-nodes.git
    version: main

I’ll leave the original for now.

Organize workspace for vscode

This reference has instructions.

When I emptied out the workspace, I got a “Clone Repository” message which sounded like a good thing to try. Also found with Ctl-Shift-P Git: Clone from the Git vscode extension.

I see I have misnamed these. Need an underscore, not a dash. Renaming everything.

From answers I also found this which is more specific for ROS2. Using it for tasks.json

OK I have build tasks working, I think I will check it in.

Debugging

Did a bunch of work, now can debug C++ in vscode! See checkins.

Here are full instructions starting from a bash prompt with ros2 sourced:

mkdir -p fqdemo-ws/src
cd fqdemo-ws
wget https://raw.githubusercontent.com/rosdabbler/fqdemo/main/fqdemo_ssh.repos
vcs import src < fqdemo_ssh.repos
colcon build
source install/setup.bash
code
# Add to workspace these folders in order: src/fqdemo-nodes, src/fqdemo-msgs, ./
# save as ./fqdemo.code-workspace and exit
code fqdemo.code-workspace

In code:

• set a breakpoint at fqdemo_nodes/src/demo_sub_pub.cpp at rclcpp::init(argc, argv);
• open “RUN AND DEBUG” from side icon
• In run select ‘(gdb) subpub debug(fqdemo_nodes)

Hmmm, did not work. I bet I did not compile with debug symbols? Retried:

rm -r build install log
colcon build --cmake-args '-DCMAKE_BUILD_TYPE=Debug'
# etc.

This time it worked (that is, it stopped on the breakpoint unlike before). So it is important to add debug symbols to the build.