Okay this was a deep dive into clearml-agent code 😁
Took a long time to figure out that there was a specific Python version with a specific virtualenv that was old (Python 3.6.9 and Python 3.8 had latest virtualenv, but Python 3.7.5 had an old virtualenv).
Then the task requested to use Python 3.7, and that old virtualenv version was broken.

As a result -> Could the agent maybe also output the virtualenv version used with setting up the environment for the first time?