"Request textDocument/completion failed" was the first thing I saw when starting to type in vscode.dev

[Tyriar]

Testing microsoft/vscode-jupyter#10170

Approx repro:

1. Open https://insiders.vscode.dev/
2. Install Python/Jupyter extensions
3. Connect to a Jupyter server (probably doesn't matter)
4. Open a folder
5. Create test.py in folder root
6. Type something

This might be related to the save dialog, if so this should be a silent failure imo.

Python language server log:

[Info  - 10:39:03] Pylance language server 2022.5.3 (pyright 73c82fab) starting
[Info  - 10:39:03] Server root directory: /
Notebook support: Legacy
[Info  - 10:39:04] No configuration file found.
[Info  - 10:39:04] No pyproject.toml file found.
[Warn  - 10:39:04] stubPath /vscode/typings is not a valid directory.
[Info  - 10:39:04] Searching for source files
[Error - 10:39:04] File or directory "/vscode" does not exist.
[Info  - 10:39:04] No source files found.
[Error - 10:43:25] Request textDocument/completion failed.
  Message: Request textDocument/completion failed with message: request cancelled
  Code: -32603 
[Error - 10:43:26] Request textDocument/completion failed.
  Message: Request textDocument/completion failed with message: request cancelled
  Code: -32603 

[Tyriar]

Saw this one when reloading vscode.dev with a notebook open:

[Info  - 15:45:40] No pyproject.toml file found.
[Warn  - 15:45:40] stubPath typings is not a valid directory.
[Info  - 15:45:41] Searching for source files
[Info  - 15:45:41] No source files found.
[Info  - 15:45:41] No pyproject.toml file found.
[Warn  - 15:45:41] stubPath typings is not a valid directory.
[Info  - 15:45:41] Searching for source files
[Info  - 15:45:41] No source files found.
[Info  - 15:45:43] [FG] Long operation: parsing: [virtual] /typeshed-fallback/stdlib/builtins.pyi (2543ms)
[Error - 15:45:46] Request textDocument/foldingRange failed.
  Message: Request textDocument/foldingRange failed with message: request cancelled
  Code: -32603 
[Error - 15:45:46] Request textDocument/foldingRange failed.
  Message: Request textDocument/foldingRange failed with message: request cancelled
  Code: -32603 

[Tyriar]

FYI I've been seeing this a lot, it's probably related to my setup (no workspace folder, non-python workspace folder) but it really doesn't look good from a user's perspective.

[Tyriar]

While playing around with notebooks/variable viewer:

[heejaechang]

dupe of #2743