When I run
hailctl dataproc start my-cluster
I get this error:
(gcloud.dataproc.clusters.create) NOT_FOUND: The resource 'projects/my-gcp-project/global/networks/default' was not found
This means that your Google Cloud project is not configured with a default network. When you have this kind of Google Cloud project, you must explicitly specify a network with --network NAME:
hailctl dataproc start my-cluster --network NAME
You can see the available networks with
gcloud compute networks list