The problem seems to be that RemoteBranch.sprout didn't get the same update as Branch.sprout to rely on the to_bzrdir for the branch_format. I have a probable fix that I'm testing now.
In the meantime, using sftp:// instead of bzr+ssh:// URLs for the source branch should workaround the problem.
The problem seems to be that RemoteBranch.sprout didn't get the same update as Branch.sprout to rely on the to_bzrdir for the branch_format. I have a probable fix that I'm testing now.
In the meantime, using sftp:// instead of bzr+ssh:// URLs for the source branch should workaround the problem.