Can't upgrade jails to 8.0

[Martin Turgeon]

Hi everyone!

I just upgraded a 7.2-REL to 8.0RC1 using freebsd-update. The upgrade 
went fine on the base system following the procedure written in the 
announcement email by Ken Smith. My problem is when I try to upgrade my 
jails, I get this message:

# freebsd-update -b /usr/jail/mysql/ fetch install
Looking up update.FreeBSD.org mirrors... 3 mirrors found.
Fetching metadata signature for 8.0-RC1 from update5.FreeBSD.org... done.
Fetching metadata index... done.
Inspecting system... done.
Preparing to download files... done.

No updates needed to update system to 8.0-RC1-p0.
No updates are available to install.
Run '/usr/sbin/freebsd-update fetch' first.

But, if I compare the dates of the files in the base system to the files 
in the jails, it's obvious that the jails are not up to date.

It seems like freebsd-update doesn't care about the basedir I specified.

Thanks a lot for your help,

Martin