Was looking for a way to set python3.12 for system or specific project.

found this gist for Ubuntu under WSL2

https://gist.github.com/4sskick/19f071f0b454849b03c31d753527d86a

But I hope last four  lines are universal:

{ cd to cinelerra-gg's source root where autogen.sh is first, I think }

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- when everything are done, ready to create venv `python3.12 -m venv venv`
 - do activate the virtual env `source venv/bin/activate`
- check python version using on venv `python --version`
- do deactivate the virutal env just type `deactivate` on root project

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