macOS: No error generated when webots-controller cannot find executable

[matl-hsk]

Describe the Bug
webots-controller prints "starting matlab" even if no matlab executable is found (at least on Mac).

Steps to Reproduce

1. Ensure that webots-controller does not find the installed matlab version (e.g. not on the global path) and don't specify it explicitly.
2. Start webots-controller with a matlab controller.

Expected behavior
An error should be printed that no matlab version was found.

System

• macOS 13.4.1
• Matlab 2023a

Additional context
See discussion in #6366

[nilsjor]

Could I ask you to provide the full path to MATLAB on your machine? By default, it will look for it at:

• /Applications/MATLAB_R20XXx.app

As per the docs https://cyberbotics.com/doc/guide/running-extern-robot-controllers?tab-language=matlab&tab-os=macos#running-a-matlab-extern-robot-controller

Is your installation located there?

[matl-hsk]

That is correct. In the webots gui it works as intended and can find the installed Matlab version.

[nilsjor]

Please tell me if I am on to something with #6388. I have no experience with macOS, and I have no machine to test it on.

[matl-hsk]

Unfortunately, this does not help.

[nilsjor]

It seems that you have the Application in the correct place -- just that the automatic invocation string is formed incorrectly. This is why no errors are given, because a valid installation is found.

1. Can you please provide the exact "matlab-path" arg that results in sucessfully running?
2. Is the .app filetype necessary? What happens if you omit it?
3. If you manually provide an incorrect path, what happens then?

[matl-hsk]

Thought it is probably faster if I just fix it myself. Thereby I realised that the selection process of the latest matlab version contained a bug, as well. Both are fixed with my PR.

[omichel]

I assume we can now close this issue. Feel free to re-open if needed.