Exit Debugger when Debugger gets stuck in a loop

I am trying to exit Debugger, but everything I have tried resulted in this error.

I have tried stop, dbquit, Ctrl+C, Shift-F5. I have also tried to use the red stop button on the Debugger toolbar. But I still have the K>> prompt and I can't run anything else.

Is there a way to clear and stop the debugger from Matlab Online so that I could do anything else?

Maximum recursion limit of 504 reached.

Error in matlab.internal.debugger.breakpoints.getGlobalBreakpoints

Caused by:
    Maximum recursion limit of 504 reached.

Answer 1

[Abhishek]

Hi @Cg Gc

‘dbquit’ or ‘dbquit all’ will allow you to exit the debugger mode. But even after that, if you are not able to exit the debugger mode, you can try resetting your MATLAB Online Session and starting a new session. Here is how you can do that:

• Visit: https://drive.matlab.com
• Log in with your MathWorks account
• Click on your name in the upper right and select "Show Hidden Files"

• Locate the ‘.session’ folder and delete its contents (only the files inside, not the folder itself)
• Then go to https://matlab.mathworks.com and start a new session

Doing so should resolve the issue. You can also try the following workarounds:

• Clearing the cache and cookies and reloading the page.
• Open MATLAB Online in a different browser.
• Ensuring the browser is up to date.

For more information on managing breakpoints and debugging, you can check the official documentation of MATLAB:

• 'dbquit': https://www.mathworks.com/help/matlab/ref/dbquit.html
• 'dbquit all': https://www.mathworks.com/help/matlab/ref/dbquit.html#d126e381022

Answer 2

[Ruchika Parag]

Hi @Cg Gc, this issue occurs when the debugger gets stuck in a recursion loop and exceeds the maximum recursion limit, which corrupts the internal state. In this situation, normal exit commands like dbquit, stop, Ctrl+C, or Shift+F5 may no longer work, especially in MATLAB Online.

Here are a few things you can try:

1. Try forcing the debugger to exit:

dbclear all

This attempts to clear all breakpoints and forcibly exit debug mode. However, in severe recursion errors, this may not be effective.

2. Refresh or restart the MATLAB Online session:

If the prompt is still stuck at K>>, try refreshing your browser tab. If that doesn't work, click your profile icon (top right in MATLAB Online) and choose "End Session", then reopen MATLAB Online. This resets the current session and should clear the stuck debugger state.

3. Preventing it in the future:

This kind of issue can happen if:

• You set breakpoints inside recursive functions.
• A callback or function is triggering recursion unexpectedly.
• There's an error in breakpoint management (especially with custom logic).

Hope this helps!

[Walter Roberson]

dbquit force

force is not a valid dbquit option.