Trying to install noetic (with melodic installed) with Ubuntu Bionic
Noetic is only supported on Ubuntu Focal. You cannot install it on Ubuntu Bionic.
See also REP 3: Target Platforms - Platforms by Distribution - Noetic Ninjemys (May 2020 - May 2025).
Edit:
I saw the REP3 doc but thought it meant that Noetic packages must support Ubuntu Focal, not that Noetic would not run on Bionic.
The REP has this to say about supported platforms:
Required Support for:
- Ubuntu Focal Fossa (20.04)
Recommended Support for:
So Ubuntu Focal must be supported by packages released into ROS Noetic, while Debian Buster and Fedora 32 are to be given best effort support.
Ubuntu Bionic is not mentioned here. ROS Noetic does not support Ubuntu Bionic with binary packages (so no apt install ros-noetic-..
).
Note also: not all architectures get binary packages either. Typically only 64 bit targets are supported (ie: amd64
and arm64
). See REP-3
again.
This earlier doc suggests that it should:
If you are using the same branch for Noetic and Melodic, then use Ubuntu Bionic. That will make sure your changes continue to work on Melodic's target platform. If you are using a separate branch for Noetic, then consider using Debian Buster as that will likely be one of Noetic's target platforms.
That's a quote from the Python 3 migration guide, and the branches this text refers to are the branches in your VCS repository. For some packages it may be possible to use the same code base for both Melodic and Noetic. In that case there is no need to maintain separate versions of packages for these two ROS versions.
Note how the rest of the guide you quoted from then continuous to describe how to build ROS from source (either Melodic or Noetic, depending on which route you choose).
If Noetic requires Focal, does that mean you cannot have Melodic and Noetic on the same system?
If your question was: "can I install ROS Noetic using apt
on Ubuntu Bionic?", then the answer would be: no (see above).
In the past when I upgraded ROS, I would keep the earlier version around for a while, to use when I needed packages that had not yet upgraded.
Melodic also was only available on Bionic (and Artful (17.10) for as long as that Ubuntu release was supported by Canonical). You could not install Kinetic and Melodic on the same system.
It would be convenient, but it's not something that is supported by the ROS buildfarm configuration (ie: it does not build binary packages of Noetic for any Ubuntu version other than Focal).
Possible work-arounds:
- use Docker: once the images are available, you should be able to
docker run -it --rm ros:noetic
on any OS which is supported by Docker - build from source: it may be possible to build Noetic from source on Ubuntu versions other than Focal. A from-source build will require a bit more effort -- both the initial build ...
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