Relocate not working with externals

On FreeBSD 10.2 using subversion 1.9.3 from ports, relocating a working copy
with externals does not work.

To duplicate, create a repository containing two directories and a text file
in each directory. I created following:

    proj1
    proj1/file1.txt
    proj2
    proj2/file2.txt

Now add an external within proj1 for proj2.
    cd proj1
    svn propget svn:externals .
    ^/proj2 proj2

Commit property change to repository.

Replicate repository to a mirror repository.

Checkout proj1 from mirror

    svn co svn+ssh://mirror/svn/proj1

Relocate working group to master

    cd proj1
    svn relocate svn+ssh://master/svn/proj1

You will see error:

    svn: E155024: Invalid source URL prefix: 'svn+ssh://mirror/svn/proj1' (does not overlap target's URL 'svn+ssh://mirror/svn/proj2')

Anybody else seeing this issue?

-- 
------------------------------------------------------------------------
Larry Baird
Global Technology Associates, Inc. 1992-2012 	| http://www.gta.com
Celebrating Twenty Years of Software Innovation | Orlando, FL
Email: lab_at_gta.com                 		| TEL 407-380-0220