Provide an option to not change the selected interpreter when it doesn't exist

[brettcannon]

As noted by @ambv and @pablogsal in episode 3 of their core.py podcast, it's problematic when you select a Python interpreter that you're actively developing as the interpreter to use. This is because when you rebuild Python it will eventually delete the interpreter. The deletion triggers the extension to immediately look for another interpreter to fill in the gaps. This causes issue for Python core developers when they try to navigate to code and they end up in some installed interpreter's stdlib instead of the one they are actively working on.

Probably some setting that doesn't automatically switch the selected interpreter even if it doesn't exist would solve the issue. That way we can just pick back up when it exists again and just continue on working.

[github-actions]

Thanks for the feature request! We are going to give the community 60 days from when this issue was created to provide 7 👍 upvotes on the opening comment to gauge general interest in this idea. If there's enough upvotes then we will consider this feature request in our future planning. If there's unfortunately not enough upvotes then we will close this issue.

[ambv]

Yes, that would be great. The reason why this is important is that clicking through to definition of standard libraries for regular users opens the relevant installed Python file somewhere on the user's disk.

In our core development case, we want to click through to another file in the same checkout we are using. We are developing the standard libraries, so we expect all those files to be local. This works when the chosen interpreter is the one we built ourselves. But we rebuild it often so it can disappear momentarily. In this case we'd like the clickthrough to definition to still work because those files are still all there, it's just ./python.exe that is temporarily missing.

[brettcannon]

I'm also assuming that Pylance is getting this from us, and so this is not something to ask downstream to change.

[brettcannon]

Because this is specific for the Python development team, we are granting an exception for the upvote requirement and are going to keep this open.