Installation instructions on Ubuntu 24.04 and Jazzy

[mcamurri]

A big thank you to the developers of this script.

I'm trying ROS2 for the first time now and I'm shocked by the amount of changes and missing features ROS2 has compared to ROS1. This fixes some of them.

While attempting to install the package following your instructions, my freshly installed Ubuntu 24.04 stops me with this error message:

error: externally-managed-environment

× This environment is externally managed
╰─> To install Python packages system-wide, try apt install
    python3-xyz, where xyz is the package you are trying to
    install.
    
    If you wish to install a non-Debian-packaged Python package,
    create a virtual environment using python3 -m venv path/to/venv.
    Then use path/to/venv/bin/python and path/to/venv/bin/pip. Make
    sure you have python3-full installed.
    
    If you wish to install a non-Debian packaged Python application,
    it may be easiest to use pipx install xyz, which will manage a
    virtual environment for you. Make sure you have pipx installed.
    
    See /usr/share/doc/python3.12/README.venv for more information.

note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
hint: See PEP 668 for the detailed specification.

I diligently installed everything in a virtual environment inside a python folder in my home, but what's the recommended installation procedure to make ros-command's commands available?

Should I just stick some extra export PATH=$HOME/python/bin:$PATH and export PYTHONPATH=$HOME/python/lib/python3.12/site-packages:$PYTHONPATH to my .bashrc ?

[mcamurri]

UPDATE:

I just tried the above and roscd turtlesim gives me this:

Traceback (most recent call last):
  File "/home/mcamurri/python/bin/get_ros_directory", line 5, in <module>
    from ros_command.commands.get_ros_directory import main_get_dir
  File "/home/mcamurri/python/lib/python3.12/site-packages/ros_command/commands/get_ros_directory.py", line 9, in <module>
    from ros_command.completion import PackageCompleter
  File "/home/mcamurri/python/lib/python3.12/site-packages/ros_command/completion.py", line 6, in <module>
    from ros_command.packages import get_all_packages, get_packages_in_folder, get_launch_file_arguments
  File "/home/mcamurri/python/lib/python3.12/site-packages/ros_command/packages.py", line 3, in <module>
    from rosdep2.ament_packages import get_packages_with_prefixes, AMENT_PREFIX_PATH_ENV_VAR
ModuleNotFoundError: No module named 'rosdep2'

same for the other commands, e.g. rosbuild.

Outputs of:

• python --version: Python 3.12.3
• uname -r: 6.11.0-25-generic

[DLu]

The short answer is that doing a global pip install like the instructions recommend is technically bad practice, and you can get around it (as I do) by using the break-system-packages option.

pipx might be a bit easier, but I haven't played with it.

RE: Your update - Usually rosdep2 gets installed with ROS. What do you get when you type which rosdep

[mcamurri]

Hi @DLu thanks for the prompt answer. By experience, Python i pretty delicate, so if you could suggest an alternative installation instruction that follows good practice, it would be appreciated.

My which rosdep call returns the following:

/usr/bin/rosdep

[v4hn]

@DLu Any plan for a python3-ros-command package in Debian? :-) Maybe you can get @jspricke to support it?

I'm pretty sure @rhaschke would also be ok with including it in the techfak ROS-O repository
to make it available for ROS-O and ROS2 in parallel. :)

I just tried the above and roscd turtlesim gives me this: [...] ModuleNotFoundError: No module named 'rosdep2'

@mcamurri your problem is quite likely that your virtualenv does not include system site packages. It's a config option in venv/pyvenv.cfg or virtualenv --system-site-packages for a new env.

[DLu]

@v4hn Created #47 for tracking the Debian efforts.

[oscar-lima]

To install with pipx under Ubuntu 24.04 - jazzy, one can do:

sudo apt install pipx
pipx install ros-command
pipx inject ros-command rosdep2      # solves the ModuleNotFoundError: No module named 'rosdep2'
export PATH=$PATH:$HOME/.local/bin