Python 3.12+ support

[mbells]

My company uses ROS 1 and i'm involved with updating our code and ROS to support Python 3.12 to 3.14. As you may be aware, there are a number of packages that are no longer available. This includes distutils, nose, imp, six, ...

Has anyone else run into this? It seems that there are no patches to the ros-o repos i've checked that migrate away from these. Would there be interest in me submitting PRs for this?

[jspricke]

Hi Metthew,

Debian unstable is switching to Python 3.14 right now and tests pass so for those packages in Debian it probably just works (I think we upstreamed most of the patches).

[jspricke]

For example, https://github.com/ros-o/catkin still refers to nose. It does not have pytest support. The nose package does not work with Python 3.14. It also refers to distutils, which was removed in Python 3.12.

AFAIR that only affects packages that use those functions from catkin, not the package itself.

The ros-o/ros_comm package has similar problems...

What do you mean by similar?

[mbells]

Our build is a bit more pedantic than the standard one, so when package.xml declares a dependency on nose, it cannot be found so the build fails. Perhaps others only have problems if they try to run tests? Which we do as well within our CI pipeline.

For reference, sample commands i'm running on ros_comm (the only package in the workspace, but getting lots from rosdistro):

colcon build --mixin ws-test --packages-select test_rospy
colcon test --event-handlers console_direct+ --packages-select test_rospy

[jspricke]

Ah, Debian does not use colcon nor the package.xml but rather has it's own metadata: https://salsa.debian.org/science-team/ros-catkin/-/tree/debian/latest/debian?ref_type=heads incidentally I have remove python3-nose there in 2022: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1018622

[mbells]

Interesting. What do you expect to happen when a project calls catkin_add_nosetests? I think what would happen is without nose being found, it would warn and skip the tests.

[jspricke]

yes, from what I can see here: https://buildd.debian.org/status/fetch.php?pkg=ros-ros-comm&arch=amd64&ver=1.17.4%2Bds-4&stamp=1773251346&raw=0

[v4hn]

Related discussion: #23 (comment)

Patches to upstream (or de-facto upstream in ROS-O repos) for current python support are clearly welcome.
Please post here if you experience any problems with contributing.
It would be a horrible loss of time for various people if prepared patches do not make it to public repos.

The main policy for this organization is to stay backward-compatible in the default branch (usually obese-devel) where possible, though at some point we will need to introduce a new branch. As we want to stay with O for obvious reasons, we can iterate the second letter instead. So I suggest occult-devel where we need it :-).