I just chatted with Derek about this, and while we identified some potential regressions (previously we were injecting str(prompt) into Activate.ps1, and now we're showing repr(prompt)), I don't think they're widely used.

For example, if you previously did:

>>> py -m venv --prompt "my`nprompt" env

You'd get 'my\nprompt' in pyvenv.cfg, but an actual newline in your printed prompt (note that passing "my\nprompt" in the command doesn't do this). There are likely other things that will be escaped in the configuration that previously would have been fine with the direct substitution.

I have no real sense of how widely used these are. They are definitely less popular than machines that are configured to require code-signed Powershell scripts, so we still come out ahead. It's probably easy to handle some of the more common escapes, if we know what they are, but I doubt we're going to reimplement full Python string parsing in a Powershell script.

Vinay - any thoughts here? For me, I think get it out in 3.8.0b4 and see how it fares.