Hi Bojan,

Dear Sirs,

I guess this is not the right address. Just saying.

I have a hard time to cross-compile and to properly include the custom ROS2 foxy package into the Yocto image. I properly added meta-ros layer and ROS2 foxy distro to our Yocto build by following instructions from here (Sanity Tests pass successfully).

I wanted to use a devtool and build a simple custom ROS2 package containing publisher and subscriber nodes. The source code of the package is on the git - link.

I used tips and tricks from here to create ROS2 recipes with the devtool. My custom bitbake recipe for the simple ROS2 package looks like this (my-first-yocto-pkg_git.bb file):

DESCRIPTION = "Example of minimal publisher/subscriber using rclcpp."
LICENSE = "Apache-2.0"
LIC_FILES_CHKSUM = "file://package.xml;beginline=8;endline=8;md5=3a75fd635766e2f76c3d90ee6495f310"

SRC_URI = "git://github.com/bojankoce/ros2pkg;protocol=https"

# Modify these as desired
PV = "0.1.0"
SRCREV = "1312445de2e6861d9561c0f89f4827b94c2ff6b1"

DEPENDS = "rclcpp std-msgs"

S = "${WORKDIR}/git"

# NOTE: unable to map the following CMake package dependencies: rclcpp ament_lint_auto std_msgs ros_ament_cmake
inherit ros_ament_cmake

However, when I tried to build the package with the devtool build my-first-yocto-pkg command, I get the following error:

CMake Error at CMakeLists.txt:19 (find_package):
  By not providing "Findament_cmake.cmake" in CMAKE_MODULE_PATH this project
  has asked CMake to find a package configuration file provided by
  "ament_cmake", but CMake did not find one.

  Could not find a package configuration file provided by "ament_cmake" with
  any of the following names:

    ament_cmakeConfig.cmake
    ament_cmake-config.cmake

  Add the installation prefix of "ament_cmake" to CMAKE_PREFIX_PATH or set
  "ament_cmake_DIR" to a directory containing one of the above files.  If
  "ament_cmake" provides a separate development package or SDK, be sure it
  has been installed.

The issue is around ament_cmake. I included the inherit ros_ament_cmake line into the recipe but this does not help. Do you have any idea about what I am missing here? Is there any better way to cross-compile and include a custom ROS2 foxy package into the Yocto image?

You are missing a DEPENDS, ros_ament_cmake does not add it. Try adding ament-cmake-native to your DEPENDS and see if that works (or give you a different error message, since I guess you might be missing out more stuff).

Regards,

   Matthias

Hello, Matthias.

I added `amente-cmake-native` inti DEPENDS and, indeed, I got a different error this time:

Initialising tasks: 100% |######################################################################################################| Time: 0:00:02
Sstate summary: Wanted 0 Local 0 Network 0 Missed 0 Current 578 (0% match, 100% complete)
NOTE: Executing Tasks
NOTE: my-first-yocto-pkg: compiling from external source tree /home/bojan/var-fslc-yocto-playground/build_xwayland/workspace/sources/my-first-yocto-pkg
ERROR: my-first-yocto-pkg-0.1.0-r0 do_package: QA Issue: my-first-yocto-pkg: Files/directories were installed but not shipped in any package:
  /usr/share/my_first_yocto_pkg
  /usr/share/my_first_yocto_pkg/local_setup.zsh
  /usr/share/my_first_yocto_pkg/local_setup.bash
  /usr/share/my_first_yocto_pkg/package.xml
  /usr/share/my_first_yocto_pkg/local_setup.sh
  /usr/share/my_first_yocto_pkg/package.dsv
  /usr/share/my_first_yocto_pkg/local_setup.dsv
  /usr/share/my_first_yocto_pkg/environment
  /usr/share/my_first_yocto_pkg/cmake
  /usr/share/my_first_yocto_pkg/environment/path.sh
  /usr/share/my_first_yocto_pkg/environment/path.dsv
  /usr/share/my_first_yocto_pkg/environment/ament_prefix_path.dsv
  /usr/share/my_first_yocto_pkg/environment/ament_prefix_path.sh
  /usr/share/my_first_yocto_pkg/cmake/my_first_yocto_pkgConfig.cmake
  /usr/share/my_first_yocto_pkg/cmake/my_first_yocto_pkgConfig-version.cmake
  /usr/lib/my_first_yocto_pkg/talker
  /usr/lib/my_first_yocto_pkg/listener
Please set FILES such that these items are packaged. Alternatively if they are unneeded, avoid installing them or delete them within do_install.
my-first-yocto-pkg: 17 installed and not shipped files. [installed-vs-shipped]
ERROR: my-first-yocto-pkg-0.1.0-r0 do_package: Fatal QA errors found, failing task.
ERROR: Logfile of failure stored in: /home/bojan/var-fslc-yocto-playground/build_xwayland/tmp/work/cortexa53-crypto-fslc-linux/my-first-yocto-pkg/0.1.0-r0/temp/log.do_package.15149
ERROR: Task (/home/bojan/var-fslc-yocto-playground/build_xwayland/workspace/recipes/my-first-yocto-pkg/my-first-yocto-pkg_git.bb:do_package) failed with exit code '1'
NOTE: Tasks Summary: Attempted 2200 tasks of which 2192 didn't need to be rerun and 1 failed.
NOTE: Writing buildhistory
NOTE: Writing buildhistory took: 3 seconds

Summary: 1 task failed:
  /home/bojan/var-fslc-yocto-playground/build_xwayland/workspace/recipes/my-first-yocto-pkg/my-first-yocto-pkg_git.bb:do_package
Summary: There was 1 WARNING message shown.
Summary: There were 2 ERROR messages shown, returning a non-zero exit code.

I needed to append the following lines at the end of my-first-yocto-pkg_git.bb file in order to resolve it:

FILES_${PN} += "/usr/share/my_first_yocto_pkg/*"
FILES_${PN} += "/usr/lib/my_first_yocto_pkg/*"
FILES_${PN}-dev = "/usr/share/my_first_yocto_pkg/* /usr/lib/my_first_yocto_pkg/* ${includedir}"

In addition to the above changes, I also included instructions inside conf/local.conf file to install my first ROS2 package:

IMAGE_INSTALL_append=" ros-core my-first-yocto-pkg"

After that, I was able to bitbake the complete Yocto image, put it on the SD card, and boot the Yocto on my devkit. After sourcing ros2_setup.sh script, I entered:

ros2 pkg list

command to list all available ROS2 packages on the system.

my_first_yocto_pkg package was on the list so I was happy and excited!

I wanted to do the final touch and launch the talker node from the packet with:

ros2 run my_first_yocto_pkg talker

However, I got the info that No executable is found! What the heck!

Do you have any idea what I did wrong in the whole process?

Appreciate your efforts!

Sincerely,
Bojan.

Hi Bojan,

you do not need the additional FILES:${PN} if your package is properly named (i.e. cmake project name same as recipe same as package). I have no clue why the executable is not found, did you source the environment before?!

Regards,

    Matthias

Hello, Matthias.

It seems the issue was around naming. Now it works fine even without FILES:${PN} at the end of .bb file.
I am now good to move forward.

Thank you very much for your assistance. It is really appreciated.

Sincerely,
Bojan.