This is incorrect, rebuild is not designed to handle new urls. However,
You can look at "Advanced Example: Tracking a Reorganized Repository"
in the manpage. Ignore the text about --follow-parent since you
already have the old stuff fetched, and start following the instructions
beginning with "# And now, we continue tracking the new revisions:"
If that fails (I don't think it would); you can always link branches
together using grafts (git-svn graft-branches tries to automate this;
but it's imperfect).
--
Eric Wong
-