What is the right process for patching a release build on the ROS2 build farm?

Question

I have a couple of packages that have recently been released on the ROS2 build farm: reach and reach_ros. reach is nominally a "ROS-independent" library that currently has no dependency on ROS2 or ament, but it attempts to build and install a Python bindings library. Currently this Python bindings library is being installed to an incorrect directory because I am not using the ament_get_python_install_dir function, which was introduced in ROS2 Humble.

I would like to apply a patch to the release branch for the reach humble build, that introduces the dependency on ament and leverages the function above. I only want to add this patch to the release build and not to the source code (so as not to introduce a dependency on ROS for this package).

Is the correct process for doing this simply pushing the patch to the patches/release/humble/reach branch of the release repository?

I was able to do this (apparently successfully) for the patches/release/noetic/reach branch. However, I was not able to do a similar thing for a different patch on the reach_ros release repo (see the history of the branch). In the case of the reach_ros release repo, the patch was somehow deleted (possibly by a subsequent call to bloom-release).

TLDR: what is the correct process for applying a patch to a release track of a library being built on the ROS2 build farm?

Answer 1

The tutorial section at http://wiki.ros.org/bloom/Tutorials/ReleaseThirdParty#Adding_an_Install_Rule_as_a_Patch has the basic workflow for patching software for release. The patches/* branches in bloom are essentially an "internal" implementation detail and they are updated when bloom picks up changes to the release/*, debian/*, or rpm/* branches.

In your case the past releases of your package will serve as having completed the git bloom-release ... step and you can proceed after that.

In fact, if you commit and push the changes to your release/* branch and run bloom-release ... again it will pick up and apply the changes for you without running git bloom-patch export.