Improve "No Python interpreter" selected prompt

[roblourens]

Environment data

• VS Code version: 1.62-insider
• Extension version (available under the Extensions sidebar): v2021.10.1317843341

I think this just showed up today, but I can't give exact repro steps. I was doing python things in different repos for awhile. At some point, I noticed that I get this notification every time I open a window with a python project

I don't usually see that. Then I noticed that I have this setting, which I definitely didn't set manually: "python.defaultInterpreterPath": "/opt/python/latest/bin/python". Removing that makes the notification go away. Is there something in the extension that adds that setting? That path does not exist for me.

[karrtikr]

Then I noticed that I have this setting, which I definitely didn't set manually:

We set it in User settings when an interpreter is chosen manually, but we never modify this setting for the workspace as far as I'm aware of.

Instead of "No Python Interpreter is selected" prompt, we should show a "Invalid Python Interpreter selected" prompt, we'll fix that with this issue.

[roblourens]

But does that mean that I would have picked an interpreter at that path? Because there is no interpreter there, so I don't know how that path was selected. And yes this was User settings, not Workspace.

[karrtikr]

I would have picked an interpreter at that path?

I would think so, maybe the path got removed with the latest python update.

One other case I can think of where we write to the setting:
This setting was earlier called python.pythonPath and we did a "one time" migration to python.defaultInterpreterPath. We used internal VSCode database storage to ensure it was only done one time.

[roblourens]

I wonder whether it would have come from codespaces or a devcontainer? I was trying those at some point. I think it should be a machine-scoped setting to avoid being synced.

[karrtikr]

Oh yes, that could happen, will double check.

[karrtikr]

The scope is set to resource as it can be configured in all scopes: user, remote, workspace or folder settings. We use the configuration target as global when updating using

update(section: string, value: any, configurationTarget?: ConfigurationTarget | boolean | null, overrideInLanguage?: boolean): Thenable<void>

API. Should it still write to User settings even in remote scenarios?

[roblourens]

I think machine-overridable might be the right scope here

[karrtikr]

FYI I have fixed the scope of setting with #17732

[karrtikr]

• Change to "Invalid python interpreter" when invalid interpreter is selected.
• In case of multiroot workspace, also mention the folder for which interpreter is invalid: Add the ability to disable the new DeprecatePythonPath feature #17693 (comment)

[karrtikr]

Also, remove Python is not installed prompt in favor of No Interpreter Selected prompt. This will ensure when users finish installing Python from windows store, it shows up without reload when following the prompt to open the interpreter list. (For #19099)

[karrtikr]

• If an invalid interpreter is selected:
  
• If no Python is installed:
  
  selecting which leads to: