Release of traitlets 5.0.0 beta 1 – please test!

Hello everyone, after 4+ years of efforts and almost throwing away dozen of PRs of contribution and reverting to 4.x being the main branch; I’m please to announce the first beta release of traitlets 5.0 beta 1:

try it by installing using pip install traitlets --pre

Traitlets is the library that powers all the Jupyter and IPython configuration system, from the CLI argument parsing to the config files. It also power all the notebook widget’s types and communication

This new version should be compatible with the current stable (4.3.3), but have a lot of internal refactor, and is only Python 3.7+.

The cli parsing may behave differently so please test extensively especially on deployments like JupyterHub, where passing arguments via spawners may give different results, in which case it might be a bug.

You can see the current (rough) changelog there