jupyterlab

@jupyterlab/debugger

A JupyterLab debugger UI extension. This extension is under active development.

Prerequisites

• JupyterLab 2.0+
• xeus-python 0.8.0+
• notebook 6+

Installation

A kernel with support for debugging is required to be able to use the debugger.

It is generally recommended to create a new conda environment to install the dependencies:

conda create -n jupyterlab-debugger -c conda-forge xeus-python=0.8.0 notebook=6 jupyterlab=2 ptvsd nodejs
conda activate jupyterlab-debugger

Then, run the following command to install the extension:

jupyter labextension install @jupyterlab/debugger

Usage

For now xeus-python is the only Jupyter kernel that supports debugging. xeus-python can be selected from the JupyterLab launcher:

Alternatively, it is also possible to switch to the xpython kernel using the kernel selection dialog:

Enable the debugger, set breakpoints and step into the code:

Development

# Create a new conda environment
conda create -n jupyterlab-debugger -c conda-forge nodejs xeus-python=0.8.0 ptvsd jupyterlab=2

# Activate the conda environment
conda activate jupyterlab-debugger

# Install dependencies
jlpm

# Build TypeScript source
jlpm build

# Link your development version of the extension with JupyterLab
jupyter labextension link .

# Rebuild TypeScript source after making changes
jlpm build

# Rebuild JupyterLab after making any changes
jupyter lab build

# Start JupyterLab with the kernel logs enabled and watch mode enabled
XEUS_LOG=1 jupyter lab --no-browser --watch

Tests

To run the tests:

# [Optional] to enable the logs for xeus-python
export XEUS_LOG=1

jlpm run test

To run tests for a specific test suite name:

jlpm run test --testNamePattern=<regex>

To run tests for a specific test module name:

jlpm run test --testPathPattern=<regex>

Inspecting debug messages

The kernelspy extension for JupyterLab can be used to inspect the debug messages sent between the debugger UI and the kernel.

To install it:

jupyter labextension install jupyterlab-kernelspy