Launching an interactive PowerShell instance with the same environment as a GitLab runner

I have a PowerShell runner runs a Python job that but spews out thousands of log messages in CI.

When I log on to the machine that runs the CI job, launch a PowerShell instance and run the same command there are no errors; so it appears that the environment in which CI job runs is missing some Python modules.

In order to diagnose the issue I’d like manually run the PowerShell instance, iteratively install some candidate modules, and rerun the initial command in order to work out what is missing.

How can I manually launch a PowerShell instance with the same environment as the runner?