Connect to an existing kernel

[fecet]

Possible to attach ipdb to an existing kernel?

Currently, ipdb starts a new kernel session each time it is called, which can be inconvenient and time-consuming. If ipdb could connect to an existing kernel session, it would be much more efficient for debugging.

I believe this feature would be useful for many developers who use ipdb in conjunction with Jupyter notebooks or other interactive environments.

[gotcha]

ipdb is a community project. PR welcome !

[fecet]

I found a workaround is to use jupyter console to connect and use ipdb in it, but the ipdb in jupyter console seems buggy and fallback to a "naive" terminal, arrow key and tab not work as in ipython per jupyter/jupyter_console#162. Why this happen?

[gotcha]

I am not a regular Jupyter user so I am afraid I cannot really help.

Nevertheless, can you detail what you mean by using ipdb in jupyter ?

[fecet]

Enter jupyter console, trigger an error like 1/0, then use %debug enter it:

You can see the name of ipdb is white, arrow keys will result escape sequences and tab will print a whitespace and wouldn't trigger completion.
If we enter ipython and do the same things, we get

where the ipdb is green, indicate it work like in ipython, and it did, we can use arrow keys to navigate history and trigger completion by tab in it.

[gotcha]

jupyter-console does not depend on ipdb as shown here: https://github.com/jupyter/jupyter_console/blob/main/pyproject.toml

I guess that the ipdb prompt displayed in jupyter-console is the IPython debugger.
IOW, issues with the ipdb in jupyter-consoleshould be reported to the maintainers of that package.

(Similarly, ipdb is a wrapper around the given debugger.)

[gotcha]

Possible to attach ipdb to an existing kernel?

Currently, ipdb starts a new kernel session each time it is called, which can be inconvenient and time-consuming. If ipdb could connect to an existing kernel session, it would be much more efficient for debugging.

The same way, I guess that the ipdb you refer here is not this package.
Did you install the ipdb package in any way ?

[fecet]

You are correct. According to the information found at jupyter/qtconsole#143 and jupyter/qtconsole#99, it appears that this is an open problem. Thank you for sharing your insight, and I apologize for opening this here