Context

I have found this issue by copying source code tree from one computer to another. I was used to copy the prepared source code tree from my home's computer to my company's computer since I do not have Visual studio installed on my company's computer.
This was allowing me to fix issues and/or test solutions on my company's computer without Visual Studio, e.g. for software I only have on my company's computer (e.g. Skype for Business, Matlab, et.)

Steps to reproduce:

• Clone NVDA source code
  By default, it is cloned in a folder named "nvda"
• Prepare the source tree (with scons source command)
• Run NVDA executing the new runnvda.bat script
  NVDA starts correctly
• Close the NVDA run from source
• Rename the folder containing the clone of NVDA's srouce code, e.g. from "nvda" to "nvda1"
• Run NVDA executing the new runnvda.bat script

Actual behavior:

An error message appears saying:

NVDA cannot detect the Python virtual environment. To run NVDA from source, please use runnvda.bat in the root of this repository.

Expected behavior:

• NVDA starts correctly
• If not possible:
  • at least this unclear message should not appear since I have actually run NVDA with the runnvda.bat script.
  • A way to restore a good configuration with the new folder name should be provided

Additional comments

Being able to copy a prepared source tree may be useful in the following situation:

• Debugging with source code on computer where Visual Studio is not installed
• Be able to save a source tree in another folder rather than committing it or stashing it

System configuration

NVDA installed/portable/running from source:

From source

NVDA version:

Version: source-master-52bf1ed

Windows version:

Windows 10 2004 (64-bit) build 19041.388

Name and version of other software in use when reproducing the issue:

N/A

Other information about your system:

N/A

Other questions

Does the issue still occur after restarting your computer?

Yes

Have you tried any other versions of NVDA? If so, please report their behaviors.

Tried some previous post-2020.4 alpha version of NVDA, where the issue was not present.

If add-ons are disabled, is your problem still occurring?

Yes

Did you try to run the COM registry fixing tool in NVDA menu / tools?

No

Issue very likely to be introduced with #12075 in 528d570.
Cc @michaelDCurran

Also Cc @lukaszgo1: if you are interested in looking at this issue.