Primarily an issue with deployments, but could also cause issues across run modes.
Currently if the env is not set up properly (e.g., for the agent - loading conda env, setting tmpdir) there is a largely silent failure and Prefect will just hang. The only clue is that the logs from the failed dask-workers will have something along the lines of "could not find temp directory".
Ideally, we should recognize the env is not set up and throw a warning, and terminate the deployment before it gets started