Cell-debugging in VSCode-Remote causes error "Canceled" "Source: Jupyter (Extension)" on second try

[flixha]

Environment data

• debugpy version: 1.4.1
• OS and version: Remote: RHEL 8.4, User: MacOS 10.13.6
• Python version (& distribution if applicable, e.g. Anaconda): python 3.8.3 via miniconda
• Using VS Code or Visual Studio: VSCode 1.61.2, commit 6cba118ac49a1b88332f312a8f67186f7f3c1643 with Remote Extension

Actual behavior

"Debug cell" only works on its first invocation, afterwards it causes the error "Canceled Source: Jupyter (Extension)" which requires a full restart of VSCode to make debugging work again.

A smaller (not sure if related) issue is that the debugger marks the "wrong" line in yellow when it is first started; it marks a line in the import-cell rather than in the debugging-cell.

Expected behavior

No "Canceled"-error. (debugging generally worked in previous versions, but I cannot say when it last worked).

Steps to reproduce:

See screen-capture below, summarized, the following workflow causes the debugger to crash with "Canceled Source: Jupyter (Extension)", which then requires a full restart of VSCode to continue with debugging:

1. Run a cell with a package import
2. Set a breakpoint and debug a cell. Complete cell-debugging with "continue" or abort debug with Stop/Disconnect. No problem on the first try.
3. Try the same as in 2 again. Now the debugger remains in a state where user can only press "Pause" or "Stop". Both cause this error to appear: "Canceled Source: Jupyter (Extension)". Debugging stops working until VSCode is restarted.

debugpy_demo.mov

[int19h]

@DonJayamanne I'm not familiar with this "canceled source" message - I'm assuming this is something from vscode-jupyter debugger integration?

[DonJayamanne]

@int19h Apologies for not getting back to you on this. I think this might be a problem at our end, could be us thrown a Cancellation error and the error message is just Cancelled, which then ends up getting displayed by VS Code.

I've tested this against the latest version of VS Code and I'm unable to repro this, possible this is a bug in the previous version of the extension.

@flixha Please could you update the latest versions of VS Code and the Jupyter extension and test this out.

[fabioz]

I'm closing this as it doesn't seem reproducible and there wasn't additional feedback.

@flixha please reopen if you're still able to reproduce in the latest version.