Matlab 2021b: Run Section in debugging mode not working anymore

I have upgraded to Matlab 2021b recently and found out that changes have been made regarding to the debugger and the 'Run section' command.

Previously, you could be debugging and interactively execute sections (either via the 'Run section' button or by hitting 'Ctrl+Enter').

This functionallity is no longer in the newest release.

What happens instead is that it seems like the 'Run section' is queued and executed after the debugger is ended.

A minimum working example:

function test()

disp('this one is printed')
%% create a section
disp('we want to print this more than once by hitting ctrl+enter')
%% doesn't matter if we create a new section here or not
disp('set a breakpoint on this line')
end

1. Set a breakpoint on the last line of the function
2. Execute function and see the output in the command window: "this one is printed" and "we want to print this more than once by hitting ctrl+enter"
3. While still being in the debugger, try to execute the section with the second disp more than once (you can use 'Ctrl+Enter' or the 'Run section' button)
4. The section is not executed, and we do not get any output
5. Exit the debugger by pressing 'Continue'
6. Output in the command window: "set a breakpoint on this line" and "we want to print this more than once by hitting ctrl+enter"

It seems like the execution from step 3 is registered, but only done AFTER the debugger is exited!

Another question having also issues with the 'Run section' functionality can be found here (there an error occurs and the debugger is not active):

https://de.mathworks.com/matlabcentral/answers/1564016-matlab-2021b-run-section-now-interrupts-currently-running-section?s_tid=srchtitle

Are there any plans to return to the original behaviour?

Answer 1

[Srijith Kasaragod]

Hi Michael,

This is a known issue and our developers are aware about it. It might be fixed in future releases.

There are no workarounds for this issue at the moment.

Regards.

[Michael Zauner]

Thanks for the reply! I am looking forward seeing that bug fixed.

Answer 2

[Marcel]

@Srijith Kasaragod

Is it planned to fix this bug with an update-release or do we need to wait for Matlab 2022?

This is a major bug that would prevent users to use 2021b in my eye, otherwise is no efficient working possible.

Is there already a time-line when we can expect a fix?