Installing ROS2 Humble on Ubuntu Mantic

Question

I got this error while trying to install ros2 humble:

Err:6 http://packages.ros.org/ros2/ubuntu mantic Release
  404  Not Found [IP: 140.211.166.134 80]
Reading package lists... Done                 
E: The repository 'http://packages.ros.org/ros2/ubuntu mantic Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Answer 1

ROS 2 Humble is not supported as a binary distribution on Ubuntu Mantic (23.10)

In general, when you run into issues like this, it is important to check what the supported platforms are for a given ROS 2 distribution. All of these are documented in REP 2000. More specifically, in this case, you would want to consult the section for Humble Hawksbill.

As a rule of thumb, ROS binary packages are available for the current LTS that was available at the release of that ROS distribution.

• Crystal Clemmys (December 2018 - December 2019) - Ubuntu Bionic (18.04)
• Dashing Diademata (May 2019 - May 2021) - Ubuntu Bionic (18.04)
• Eloquent Elusor (November 2019 - November 2020) - Ubuntu Bionic (18.04)
• Foxy Fitzroy (May 2020 - May 2023) - Ubuntu Focal (20.04)
• Galactic Geochelone (May 2021 - November 2022) - Ubuntu Focal (20.04)
• Humble Hawksbill (May 2022 - May 2027) - Ubuntu Jammy (22.04)
• Iron Irwini (May 2023 - November 2024) - Ubuntu Jammy (22.04)
• Jazzy Jalisco (May 2024 - May 2029) - Ubuntu Noble (24.04)

Rolling is in the process of being migrated to Noble to support the Jazzy release.