I have tried the script again, and looking through what the script it doing, I am confused. I am not getting the "Script is outside ProTools repository" error anymore, but I am getting that ".venv" is not "recognized as an internal or external command, operable program or batch file."

I was originally trying to run it from a folder on my non-primary hard-drive, and that did not succeed. Then, I tried to run it on my main hard-drive (my OS drive), and I was given the same error.

I added some output to try and see, myself, what is going wrong. The python command that is failing, specifically, is:
python "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\Config\ptsl_build_script.py" --target ptsl.client.cpp --conf Debug --dev OFF --source_dir "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\.." --build_dir "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\WinBuild" --install_dir "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\install\Debug\PTSLC_CPP" --ptsl_root "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\install\Debug\PTSLC_CPP" --arch x86_64 --os None

Here is my entire output:

>python3 setup/build_cpp_ptsl_sdk.py --target ptsl.client.cpp --config Debug --arch x86_64

Python Version: 3.9.6 (default, Aug 15 2021, 14:49:43)  [GCC 10.3.0 64 bit (AMD64)]
Argument list: ['setup/build_cpp_ptsl_sdk.py', '--target', 'ptsl.client.cpp', '--config', 'Debug', '--arch', 'x86_64']

Creating venv in the C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\Config
Looking in links: c:\Users\iamme\AppData\Local\Temp\tmprdhnopi_
Processing c:\users\iamme\appdata\local\temp\tmprdhnopi_\setuptools-56.0.0-py3-none-any.whl
Processing c:\users\iamme\appdata\local\temp\tmprdhnopi_\pip-21.1.3-py3-none-any.whl
Installing collected packages: setuptools, pip
Successfully installed pip-21.1.3 setuptools-56.0.0

python "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\Config\ptsl_build_script.py" --target ptsl.client.cpp --conf Debug --dev OFF --source_dir "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\.." --build_dir "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\WinBuild" --install_dir "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\install\Debug\PTSLC_CPP" --ptsl_root "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\install\Debug\PTSLC_CPP" --arch x86_64 --os None

Initializing CMake from the command: ['python', '"C:\\Users\\iamme\\Documents\\Programming\\Pro_Tools_Scripting_SDK\\PTSL_SDK_CPP.2023.3.1.0.605875\\setup\\..\\Config\\ptsl_build_script.py"', '--target', 'ptsl.client.cpp', '--conf', 'Debug', '--dev', 'OFF', '--source_dir', '"C:\\Users\\iamme\\Documents\\Programming\\Pro_Tools_Scripting_SDK\\PTSL_SDK_CPP.2023.3.1.0.605875\\setup\\.."', '--build_dir', '"C:\\Users\\iamme\\Documents\\Programming\\Pro_Tools_Scripting_SDK\\PTSL_SDK_CPP.2023.3.1.0.605875\\setup\\..\\WinBuild"', '--install_dir', '"C:\\Users\\iamme\\Documents\\Programming\\Pro_Tools_Scripting_SDK\\PTSL_SDK_CPP.2023.3.1.0.605875\\setup\\..\\install\\Debug\\PTSLC_CPP"', '--ptsl_root', '"C:\\Users\\iamme\\Documents\\Programming\\Pro_Tools_Scripting_SDK\\PTSL_SDK_CPP.2023.3.1.0.605875\\setup\\..\\install\\Debug\\PTSLC_CPP"', '--arch', 'x86_64', '--os', 'None'],

getting dependencies

.venv\bin\activate.bat && pip install -r requirements.txt && python "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\Config\ptsl_build_script.py" --target ptsl.client.cpp --conf Debug --dev OFF --source_dir "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\.." --build_dir "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\WinBuild" --install_dir "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\install\Debug\PTSLC_CPP" --ptsl_root "C:\Users\iamme\Documents\Programming\Pro_Tools_Scripting_SDK\PTSL_SDK_CPP.2023.3.1.0.605875\setup\..\install\Debug\PTSLC_CPP" --arch x86_64 --os None

'.venv\bin\activate.bat' is not recognized as an internal or external command,
operable program or batch file.