Booted 20170814 amd64 snapshot. Hit enter until I got to the Partitioning menu.
Note that the default partition type is freebsd-zfs. That's fine.
"Your changes will now be written to disk" -yep, "commit."
Get the message: Error: No root partition was found. The root FreeBSD partition must have a mountpoint of '/'.
ZFS needs a root partition set? Seems fishy.
Same behaviour for me installing 12.1-RELEASE. Note that if I *do* set a mountpoint, I receive a different error:
An installation step has been aborted. Would you like to restart the installation or exit the installer?"