How do you zfs rename a dataset that has children?

[Trent Nelson]

This has me scratching my head:

[root at usbkey/ttypts/0(~)#] zfs create tank/host/foo
[root at usbkey/ttypts/0(~)#] zfs create tank/host/foo/bar             
[root at usbkey/ttypts/0(~)#] zfs rename tank/host/foo tank/host/test
Assertion failed: (!clp->cl_alldependents), file /usr/src/cddl/lib/libzfs/../../../cddl/contrib/opensolaris/lib/libzfs/common/libzfs_changelist.c, line 470.
zsh: abort (core dumped)  zfs rename tank/host/foo tank/host/test

Say wha'?

Renaming the child dataset first works, but it's not what I want, obviously:

[root at usbkey/ttypts/0(~)#] zfs rename tank/host/foo/bar tank/host/test/bar
cannot create 'tank/host/test/bar': parent does not exist
[root at usbkey/ttypts/0(~)#] zfs rename -p tank/host/foo/bar tank/host/test/bar
[root at usbkey/ttypts/0(~)#] zfs rename tank/host/foo tank/host/test/bar    
cannot rename 'tank/host/foo': dataset already exists

[root at usbkey/ttypts/0(~)#] uname -a
FreeBSD usbkey.home.trent.me 8.2-STABLE FreeBSD 8.2-STABLE #2 r224667M: Sat Aug  6 04:11:46 EDT 2011     root at home.trent.me:/usr/obj/usr/src/sys/GENERIC  amd64

(The 'M' in r224667M is due to a device ID I changed in e1000.h; unrelated to this issue.)

What am I doing wrong?

(My actual use case is more complicated than the test case above; I built a new system, named 'fulcrum', from an existing build, named 'flanker'. I want to rename tank/host/flanker -> tank/host/fulcrum (hence booting from the usbkey).)


Regards,

	Trent.