Offer jedi users to switch to pylance (if they have pylance installed)

[isidorn]

Somehow it happened to both me and my wife that we were using the Jedi language service. My wife does not know what is Jedi and what is Pylance, she just noticed that the language support was subpar.

I am curious if there are other users that accidentally end up using the Jedi language service, and they are not aware what they are missing.

I discussed this with @luabud

Could we detect if this happens (e.g. there was an error with Pylance installation).
Or if we can not detect, should we just offer for existing Jedi users that have Pylance installed an option to switch? The language should be framed in such a way that users like my wife (that do not know what is Jedi and Pylance) can figure out that switching to Pylance will give them a better experience.

[debonte]

Could we detect if this happens (e.g. there was an error with Pylance installation).
Or if we can not detect, should we just offer for existing Jedi users that have Pylance installed an option to switch?

If we implemented these enhancments, I believe they would need to be done in vscode-python rather than Pylance.

I think figuring out if/how Pylance install is failing should be the priority. Adding a feature that tells the user how to recover from an installation failure (our fault presumably) seems weird to me.

Can we tell if there has been a recent spike in Pylance install failures? There was a recent issue from an external user that also turned out to be due to Pylance mysteriously not being installed -- #5756 (comment)

[luabud]

There hasn't been a particular spike on installation failures FWIW, at least not particular to Pylance. I agree such a notification would have to be implemented on the Python extension side, but since it'd likely be done by someone in the Pylance team, I thought it made sense to transfer to this repo.

This is very fair though:

I think figuring out if/how Pylance install is failing should be the priority

There's this upstream issue tracking this investigation for all extensions, as it doesn't seem to be a particular problem with Pylance: microsoft/vscode#190233