There's a few other mentions of this but no fixes so far.

Environment data

• VS Code version: Noticed after upgrade to 1.52, kept happening after downgrade to 1.51.
• Extension version (available under the Extensions sidebar): v2020.12.422005962
• OS and version: Windows 10 2004
• Python version (& distribution if applicable, e.g. Anaconda): 3.9, same on 3.91
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): N/A
• Relevant/affected Python packages and their versions: All
• Relevant/affected Python-related VS Code extensions and their versions: Base Python extension
• Value of the python.languageServer setting: Pylance

Expected behaviour

Message disappears and extension eventually loads.

Actual behaviour

Message doesn't disappear, extension doesn't load, "Extension host terminated unexpectedly" message appears.

Steps to reproduce:

1. Start VSCode
2. Select a python file to trigger the extension loading.

Was also able to reproduce after separately:

• reinstalling VScode
• recreating %userprofile%.vscode
• recreating %appdata%\Code
• Updating python to 3.91
• Enabling only the Python extension

Logs

Total output of OUTPUT > Python. Extension host crashes after it sits at this for a while.

Info 2020-12-15 16:12:53: Searching for workspace virtual envs in: d:\users\ben\Documents\advent-of-code-2020
Info 2020-12-15 16:12:53: Searching for workspace virtual envs in: d:\users\ben\Documents\advent-of-code-2020\.direnv
Info 2020-12-15 16:12:53: Searching for global virtual envs in: C:\Users\Ben\Envs
Info 2020-12-15 16:12:53: Searching for global virtual envs in: C:\Users\Ben\.direnv
Info 2020-12-15 16:12:53: Searching for global virtual envs in: C:\Users\Ben\.venvs
Info 2020-12-15 16:12:53: Searching for global virtual envs in: C:\Users\Ben\.virtualenvs
Info 2020-12-15 16:12:53: Searching for global virtual envs in: C:\Users\Ben\.local\share\virtualenvs
User belongs to experiment group 'pythonaa'
User belongs to experiment group 'pythonSendEntireLineToREPLcf'