release candidate 0.2-rc3 is available

[Lukas Bulwahn]

Dear meta-ros users,

I have been heavily cross-compiling 'bitbake core-image-ros-world' with the master branch of OpenEmbedded-Core, and the master and dizzy branch of the Poky Distribution.

All build errors in meta-ros are now addressed for all available machines in OpenEmbedded-Core and Poky. I have also tested that roscore and ros_chatter run with the README.md description in the qemux86-64 virtual machine. The result is now released as version 0.2-rc3 [1], and this finalizes my testing and validation for version 0.2.

If you have some spare time, please try out if this latest release candidate works with your setting and report any further problems until May 17th, 2015. If no further critical problems are reported, version 0.2 will be released on May 18th, 2015.

[1] https://github.com/bmwcarit/meta-ros/releases/tag/v0.2rc3

Lukas

[Ash Charles]

Hi Lukas,

Thanks for your hard work on putting together this release. I just
gave roscore a test on a Gumstix Overo COM and comes up just fine.

During build, I noticed this warning:
"WARNING: Function remove_packaging_data_files doesn't exist"
It looks like this function is deprecated (See 24.4.9 in [1]).

When trying to run, ros_chatter following the README here [2], I don't
have a setup.sh and, even after exporting the ROS setup (export
ROS_ROOT=/opt/ros/hydro etc.), I run into an error with catkin:
"
Could neither find file "toplevel.cmake" in any workspace nor
relative, checked the following paths:
/home/root/ws/src/catkin/cmake/toplevel.cmake
/opt/ros/hydro/catkin/cmake/toplevel.cmake
/opt/ros/hydro/lib/python2.7/cmake/toplevel.cmake
/opt/ros/hydro/share/catkin/cmake/toplevel.cmake
/opt/ros/hydro/lib/share/catkin/cmake/toplevel.cmake
"

Silly mistake on my end or is there a different procedure for testing
with ros_chatter?

[1] http://www.yoctoproject.org/docs/1.8/mega-manual/mega-manual.html
[2] https://github.com/bmwcarit/ros_chatter/tree/master

--Ash

[Lukas Bulwahn]

Dear Ash,

I also noticed the warning "WARNING: Function remove_packaging_data_files doesn't exist"  when building the images of the meta-ros layer since quite some time ago.

I thank you for investigating the origin of this warning.

For the sake of completeness, I shortly mention how the meta-ros layer historically got into the situation of causing this warning:

As stated in the README.md, the core-image-ros-* recipes are modified versions of the core-image-minimal recipe from April 2013, obtained from the OpenEmbedded-Core repository commit at that time. The poky distribution 1.4 also packaged this core-image-minimal recipe and published it around the same time, back in 2013. In the poky distributions 1.4 and earlier, the core-image-minimal recipe added 'remove_packaging_data_files' to ROOTFS_POSTPROCESS_COMMAND.

As the section 24.4.9 of the Yocto Project Mega-Manual [1] explains, since Poky version 1.5, the needed operation is handled automatically with the package_management image feature, the remove_packaging_data_files command has been removed, and hence during the rootfs build task, bitbake emits the warning:

    WARNING: Function remove_packaging_data_files doesn't exist

Due to backwards compatibility, I have left this line in the recipe, even after updating to later poky distributions, since it only was a warning and did not cause any surprises beyond this warning so far. Now, with the release 1.8 and two years since version 1.4, we assume that most users are using Poky version 1.5 or later.

As it is only a warning and not a critical error, I already proceeded with the release of version 0.2 yesterday. However, I will add a commit that addresses the warning to the repository with my next round of improvements and updates, but this is then in the development repository after the release 0.2.

To your second issue on testing with ros_chatter, I believe you misunderstood what the tool chain and the ros_chatter recipe in meta-ros already provides.

The recipe already provides the information, so that bitbake can compile the ros_chatter sources and install the executables on the target image.

To test if chatter runs on the image, you must simply add 'chatter-sender' and 'chatter_receiver' to IMAGE_INSTALL in the image recipe, e.g., in the core-image-ros-roscore.bb file.

When you now build that image recipe, e.g., invoke 'bitbake core-image-ros-roscore', you obtain an image file with the two executables, chatter_sender and chatter_receiver, located in /opt/ros/hydro/lib of this image file. You can deploy this image file to your selected hardware, boot the Linux system, and enter the busybox terminal, e.g., through the serial device.

On this terminal, you set up the shell environment as described in the USAGE section of the meta-ros' README.md file. Then you can start roscore, and the executables simply in the terminal or use roslaunch with the sender_receiver.launch file.

So there is no need to compile the ros_chatter sources on the target as described in the ros_chatter's README file.

[1] http://www.yoctoproject.org/docs/1.8/mega-manual/mega-manual.html

I hope this helps,

Lukas

[Ash Charles]

Hi Lukas,

Thanks for your detailed response.
I sent a pull-request [1] removing the post-processing command.
Hopefully this looks okay to you and that a PR is an appropriate way
to send contributions.

I tried out chatter again and it worked nicely using roslaunch.
Thanks for your help.

[1] https://github.com/bmwcarit/meta-ros/pull/323

--Ash