Yes, I mention in the article that you have to make sure the debugger has stopped running until you can run another cell, as once a debugging session has started, the kernel is suspended. As a side effect, If you re-run the same cell before the debugger has finished, the debugger UI is gone and you won’t be able to make the Notebook responsive again until you restart it. As a future improvement, I may be able to mitigate this problem by always showing a modal control to let you stop the debugger (similar to what chrome does).
You also seem to imply that it takes multiple tries for the debugger to come up. Is the debugger UI fail to appear or the source code is empty until you use the debugger controls? If the latter, we identified the same issue under some circumstances. Please try again with PixieDust 1.1.9 which was released yesterday, that fixes this reliability issue. If you find more issues, please don’t hesitate to write an issue on the Github repo.
As for supporting JupyterLab, this is on our roadmap. Stay tuned!
Thanks for trying the PixieDebugger.