README installation instructions

[holmbuar]

Description

• Expected behavior:
  Installation instructions in README, for the currently "correct" combination of ROS and Gazebo (Humble + Fortress).

• Actual behavior:
  Installation instructions for ROS Rolling in several branches README.

Steps to reproduce

Just read the README for the different branches, for example

https://github.com/gazebosim/ros_gz/tree/ros2#install

or

https://github.com/gazebosim/ros_gz/tree/humble#install

Since this pattern shows in several branches, I'm not sure if this is actually an error. Since the docs point to this repo for installing the "correct" ros_gz version, it should reflect that? Also the Gazebo answers site seems kinda sleepy, so I'm posting this "bug" here.

[holmbuar]

I'm also confused by the wording in the ROS and Gazebo install docs

I suspect the command

sudo apt-get install ros-${ROS_DISTRO}-ros-gz

is the valid command for all ROS distros, even the currently supported one? But the text says this will install ros_gz AND Gazebo?

[holmbuar]

@ahcorde it seems my issue is related to #338

It would be nice to read how to properly install ros_gz from a binary, that's all :)

[ahcorde]

Fixed here #435

I will backport this to iron and humble.

[holmbuar]

@ahcorde thanks for being so responsive, appreciated.

Please pardon me for being slow to comprehend, but I'm still confused. To me, it seems like all the branches of ros gz still require ROS Rolling (rolling dev distro?).

For example in the humble branch

https://github.com/gazebosim/ros_gz/tree/humble

README:

This branch supports ROS Rolling. See above for other ROS versions.

,or

Be sure you've installed ROS Rolling (at least ROS-Base). More ROS dependencies will be installed below.

, and the installation command is

 sudo apt install ros-rolling-ros-gz

The binary link regarding ROS Humble and Fortress does not solve my confusion. Please let me know if there is something obvious I haven't understood.

[ahcorde]

sorry, we are creating branches from rolling when there is a new release and sometime we forgot to revisit the documentation.

How about this ?

#438

[holmbuar]

That looks much better, thanks!

Just one question left: from the documentation/ web page I mentioned:

https://gazebosim.org/docs/fortress/ros_installation#installing-gazebo-with-older-versions-of-ros

, the

sudo apt install ros-humble-ros-gz

command installs both ros_gz AND Gazebo. What if the user already has a valid and "correct" Gazebo installation?

[ahcorde]

If you have already installed Gazebo, then these packages will not be installed because they are already in your system.

The second option is to have a workspace with Gazebo compiled from source, in this case you should source this workspace and that's all.

[holmbuar]

OK thanks.

Yes, I was aware of the possibility of compiling from source, as in the project template. However, I think I prefer minimizing the mix of simulation and ROS control files, in the repo being cloned to the Pi.

[azeey]

gazebosim/docs#420 addresses the comment about "Older" versions. I think the READMEs have also been updated, so can we close this issue?