how do I bzr branch to an existing directory?

I would like for my collaborators to be able to branch a project to an existing directory, since many already have the 'dir'开发者_如何学JAVA directory which mirrors my own and I would prefer to minimize path lengths...

However, bzr won't let me do this:

mkdir dir
bzr branch ~/project/trunk dir

Is there a way around this?

mkdir dir
bzr branch ~/project/trunk dir --use-existing-dir