No space left on device during freebsd-update install (stage 1)

[Patrick]

$ sudo freebsd-update install
Installing updates...
/: write failed, filesystem is full
install: ///boot/kernel/INS at 9Y2g: No space left on device

Kernel updates have been installed.  Please reboot and run
"/usr/sbin/freebsd-update install" again to finish installing updates.

I was just doing an update from FreeBSD 9.2 to 10, and my root partition
filled up on the first "install" stage (after running freebsd-update -r
10.0-RELEASE upgrade). Is there a way I can redo that first "freebsd-update
install" step? I'm concerned that the files didn't get copied over fully,
and rebooting may leave me with a broken system.

*checks man page*

Okay, so looks like I'll be doing freebsd-update rollback and start over.
Seems like freebsd-update should detect an error like a write failed
though...