Google Cloud IAM Madness

After the recent GCP outage related to IAM, I found some odd behaviour with gsutil/gcloud. A script that had faithfully run for many months stopped working with:

ServiceException: 401 Anonymous caller does not have storage.buckets.list access to project xxxx
I tried recreating the service account key used for the operation with no luck. To fix the problem, I had to create a new bucket!

gsutil mb -b on -l us-east1 gs://my-awesome-bucket123ed321/
Creating gs://my-awesome-bucket123ed321/…
gsutil ls
gs://my-awesome-bucket123ed321/
gs://<my_original_bucket_I_couldnt_see>/