Firstly, thank you for your efforts and your support.

Thanks SmugOx94 !

Are you running trains-agent in docker mode? The aforementioned scripts are executed before, the experiment is being cloned, they are meant to be a part of the docker setup, not a per experiment script.
You could try to edit the experiment and have:
Working Directory: "."
(that means the root of the repository)

Script Path: "experiments_that_uses_library/train.py"

This will make sure you can do "import library" without the need to actually install it (the working directory will be part of the python path)
What do you think?