cloud-foundation-toolkit | The Cloud Foundation toolkit provides GCP best practices | AWS library

In Cloud Storage, objects are immutable, which means that an uploaded or created object cannot change through its storage lifetime. This means that buckets can't be renamed.

Cloud Storage > Doc > Bucket naming guidelines > Bucket name requirements:

• A bucket name can only be assigned during creation. You cannot change the name of an existing bucket. Instead, you should create a new bucket with the desired name and move the contents from the old bucket to the new bucket. See Moving and Renaming Buckets for a step-by-step guide.

Cloud Storage > Doc > Moving and renaming buckets:

When you create a bucket, you permanently define its name. However, you can effectively move or rename your bucket:

• If there is no data in your old bucket, delete the bucket and create another bucket with a new name.

According to the error message, the second deployment does not have problems with the creation of a new bucket Y, but lacks permissions on the previously created bucket X.

By default the Google APIs Service Agent account used by Deployment Manager is granted the Project Editor role: