Yes, I do have my files in the git repo. Although I have not quite understood which part it takes from the remote git repo, and which part it takes from my local system.
It seems that one also needs to explicitly hand in the git repo in the pipeline and task definitions via PipelineController, since otherwise, the agent would start the task process in some random working directory, where, of course, it cannot find any own module.

And a second thing: When starting a pipeline, it seems that ClearML would take my local virtual environment and extract its dependencies from that, independent of the requirements.txt or pyproject.toml I have in my repo. I noticed that, because I happened to installed my own project locally into my virtual env (let's call it foo==0.1), and when I started the pipeline, on the agent it looked for a package called foo==0.1 which it didn't find on PyPI (obviously) and thus the pipeline failed. Can I tell ClearML to please not take my local virtual env, but rather install what it needs directly only from the req or .toml files?

And a third thing: The pipeline installs dependencies. Also, the tasks install dependencies, too. How do I avoid redundant dependency installations?