It looks like there have been recent changes to https://github.com/plotly/plotly.py/blob/main/commands.py that mean the steps for updating plotly.js dev version no longer work Here https://github.com/plotly/plotly.py/blob/main/CONTRIBUTING.md#using-a-development-branch-of-plotlyjs - Arguments for specifying the repo and branch as documented no longer work I think it may be related to the conversion to `argparse` https://github.com/plotly/plotly.py/pull/5218 @gvwilson