Add initial BuildStream backend

[juergbi]

This adds a generator for BuildStream elements. https://github.com/CodethinkLabs/ros2-bst is a working BuildStream project for a subset of ROS Iron where all elements for ROS packages have been generated by this branch of superflore. It also includes manually written elements for some external dependencies and depends on freedesktop-sdk for the base system and other external dependencies.

It currently cannot generate elements for all packages of a ROS distro as some packages require additional external dependencies. It's thus necessary to invoke superflore-gen-bst with the --only option to specify the target packages. Elements are also generated for internal dependencies of target packages.

The generated elements currently do not include test dependencies and test suites of packages are not run as part of the build process. This should be added as a future enhancement.

[robwoolley]

Thanks for this contribution. Sorry for the delay. I am just ramping up as the new maintainer.

I tested your modifications with the following steps:

git clone https://github.com/CodethinkLabs/ros2-bst
git clone https://gitlab.com/freedesktop-sdk/freedesktop-sdk
superflore-gen-bst --ros-distro iron --output-repository-path ros2-bst --dry-run --only rclcpp

And got the error:

>>>> Regenerating package 'rti_connext_dds_cmake_module'...
Traceback (most recent call last):
  File "/home/rosuser/superflore/venv/bin/superflore-gen-bst", line 33, in <module>
    sys.exit(load_entry_point('superflore==0.3.3+14.ga343862', 'console_scripts', 'superflore-gen-bst')())
  File "/home/rosuser/superflore/venv/lib/python3.10/site-packages/superflore-0.3.3+14.ga343862-py3.10.egg/superflore/generators/buildstream/run.py", line 160, in main
  File "/home/rosuser/superflore/venv/lib/python3.10/site-packages/superflore-0.3.3+14.ga343862-py3.10.egg/superflore/generators/buildstream/gen_packages.py", line 109, in regenerate_pkg
  File "/home/rosuser/superflore/venv/lib/python3.10/site-packages/superflore-0.3.3+14.ga343862-py3.10.egg/superflore/generators/buildstream/gen_packages.py", line 215, in element_text
  File "/home/rosuser/superflore/venv/lib/python3.10/site-packages/superflore-0.3.3+14.ga343862-py3.10.egg/superflore/generators/buildstream/bst_element.py", line 261, in get_element_text
  File "/home/rosuser/superflore/venv/lib/python3.10/site-packages/superflore-0.3.3+14.ga343862-py3.10.egg/superflore/generators/buildstream/bst_element.py", line 222, in get_dependencies
superflore.exceptions.UnresolvedDependency: external dependency rti-connext-dds-6.0.1 missing

Can you provide any guidance on what is supported?

Cheers,
Rob

[juergbi]

rti-connext-dds-6.0.1 is an external dependency that is not currently included in the ros2-bst repository. You can pass --skip-keys rmw_connextdds to disable rmw_connextdds and with that, avoid the missing external dependency. With this option, your command completes successfully here.

External dependencies can be added to ros2-bst as needed without requiring changes in superflore.

[robwoolley]

Thanks for the quick reply. Running the following completed successfully:

superflore-gen-bst --ros-distro iron --output-repository-path ros2-bst --dry-run --only rclcpp --skip-keys rmw_connextdds

which updated the following files:

ros2-bst/elements/generated/ament-cmake/ament-cmake-core.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-export-definitions.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-export-dependencies.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-export-include-directories.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-export-interfaces.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-export-libraries.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-export-link-flags.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-export-targets.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-gen-version-h.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-gmock.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-gtest.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-include-directories.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-libraries.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-pytest.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-python.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-target-dependencies.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-test.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake-version.bst
ros2-bst/elements/generated/ament-cmake/ament-cmake.bst
ros2-bst/elements/generated/cyclonedds/cyclonedds.bst
ros2-bst/elements/generated/fastrtps/fastrtps.bst
ros2-bst/elements/generated/libstatistics-collector/libstatistics-collector.bst
ros2-bst/elements/generated/rcl/rcl-yaml-param-parser.bst
ros2-bst/elements/generated/rcl/rcl.bst
ros2-bst/elements/generated/rclcpp/rclcpp.bst
ros2-bst/elements/generated/rcpputils/rcpputils.bst
ros2-bst/elements/generated/rcutils/rcutils.bst
ros2-bst/elements/generated/rmw-fastrtps/rmw-fastrtps-cpp.bst
ros2-bst/elements/generated/rmw-fastrtps/rmw-fastrtps-dynamic-cpp.bst
ros2-bst/elements/generated/rmw-fastrtps/rmw-fastrtps-shared-cpp.bst
ros2-bst/elements/generated/rmw-implementation/rmw-implementation.bst
ros2-bst/elements/generated/ros2-tracing/tracetools.bst

[robwoolley]

What are the future plans for the BuildStream backend?

Will you or CodeThink be maintaining it going forward?

Since ROS 2 Iron is now end-of-life, will you be adding support for Humble, Jazzy, or Rolling?