client.load_bucket tries to fetch bucket region even if both --bucket and --region are provided as parameters.

It means that if user is not authorized to use buckets meta APIs like List Buckets or Get Bucket Location, user won't be able to use the bucket in any way. Even when user is authorized to list particular bucket content. From my experience having rights only to bucket content is not uncommon.

I've tested, and if I disable the call to get_bucket_location and replace it with region provided, other functionality works as expected.

Additionally, error in the application does not describe the real reason. Just says "No bucket found (region: us-east-1)".