Jérémie du Boisberranger

Looking at the past runs, this job fails every once in a while with this kind of error: ``` ##[error]Exit code 137 returned from process: file name '/home/vsts/agents/3.234.0/externals/node20_1/bin/node', arguments '"/home/vsts/work/_tasks/CmdLine_d9bafed4-0b18-4f58-968d-86655b4d2ce9/2.231.1/cmdline.js"'....

Fixed by #28399

Not at all, but in fetchers it's rather easy to add a progress bar.

> Could you add rich as an optional dependencies such that we have the CI using it. I'm not sure how to do that. I guess I need to edit...

Hi @rth, I think this is getting ready for a second review :) This PR introduces the base infrastructure for callbacks and a first callback for progress bars. Next steps...

Note that this PRis targeting the ``callbacks`` branch, not main so merging this is not a big commitment anyway 😄 And it would allow me to implement the rest that...

I still need to figure out the issue with the CI though EDIT: good now

Even if the diff is big, it's just moving stuff around. I did not modify a single line of actual code :smile:

> One question: should we keep exposing things that used to be in sklearn.utils in that place? - For public functions (i.e. listed in ``classes.rst``), I still left them exposed...

Everything has been moved outside of ``utils.__init__`` in individual PRs. We can close this one.