I think you may still need at least one more ROS1 release on an LTS Ubuntu distro – here’s why:
- ROS2 isn’t fully featured yet – as an example: actions will hopefully be part of the upcoming release, but I can imagine it taking 1-2 release cycles at a minimum to get those fully ironed out.
- Until those features are there, some large portion of the developer and code base will not end up on ROS2 (I can imagine that the trajectory will be very similar to ROS1 – a few folk outside the core team end up using the C-release, but the majority of the community shows up for D- or E-releases). Even if they start to use ROS2, they’ll probably be bridging things in from ROS1.
- If we suggest that the E release will be the first very highly useable release, then I think E ends up supporting Ubuntu 18.04 (since it is tail end of 2019?)
- However, ROS2 releases after that will probably end up supporting Ubuntu 20.04 and not 18.04 – meaning that you no longer have ROS1 packages to bridge over to your ROS2 installation. Right?
To me, that says that after April 2020 (only about 18 months away), it gets a lot harder to run the current ROS2 release with any ROS1 packages bridged in. Is that logic right? By releasing ROS1 on Ubuntu 20.04, you can an extra 2 years of bridge availability.
-Fergs