bectl: cannot promote 'zroot/ROOT/r364030-OpenZFS2': not a cloned filesystem

I'm still on r364030 using sysutils/openzfs 2020081800 (compiled from
ports)

pkg info -s openzfs
openzfs-2020081800             15.3MiB

I currently only have 1 BE and would like to attempt to upgrade to
anything past r364746
I don't use encryption, won't attempt an 'zpool upgrade' of zroot so think I should be safe to move forward.

# bectl list -aDs
BE/Dataset/Snapshot          Active Mountpoint Space Created

r364030-OpenZFS
  zroot/ROOT/r364030-OpenZFS NR     /          15.2G 2020-08-22 22:46


create new BE

# bectl create r364030-OpenZFS2
root_at_harbinger:~ # bectl list -aDs
BE/Dataset/Snapshot                                  Active Mountpoint Space Created

r364030-OpenZFS
  zroot/ROOT/r364030-OpenZFS                         NR     /          15.2G 2020-08-22 22:46
  r364030-OpenZFS_at_2020-08-30-19:23:04-0              -      -          0     2020-08-30 19:23

r364030-OpenZFS2
  zroot/ROOT/r364030-OpenZFS2                        -      -          8K    2020-08-30 19:23
    zroot/ROOT/r364030-OpenZFS_at_2020-08-30-19:23:04-0 -      -          0     2020-08-30 19:23

activate new BE

# bectl activate r364030-OpenZFS2
cannot promote 'zroot/ROOT/r364030-OpenZFS2': not a cloned filesystem
Did not successfully activate boot environment r364030-OpenZFS2


# zfs get origin zroot/ROOT/r364030-OpenZFS2
NAME                         PROPERTY  VALUE                                             SOURCE
zroot/ROOT/r364030-OpenZFS2  origin    zroot/ROOT/r364030-OpenZFS_at_2020-08-30-19:23:04-0  -


Despite the warning/erros messages listed a 'bectl list' does show that the new BE will be active on reboot

# bectl list -aDs
BE/Dataset/Snapshot                                  Active Mountpoint Space Created

r364030-OpenZFS
  zroot/ROOT/r364030-OpenZFS                         N      /          15.2G 2020-08-22 22:46
  r364030-OpenZFS_at_2020-08-30-19:23:04-0              -      -          0     2020-08-30 19:23

r364030-OpenZFS2
  zroot/ROOT/r364030-OpenZFS2                        R      -          8K    2020-08-30 19:23
    zroot/ROOT/r364030-OpenZFS_at_2020-08-30-19:23:04-0 -      -          0     2020-08-30 19:23


However the boot fails dropping me to the mountroot prompt.

Luckily activating r364030-OpenZFS again is not a problem and the system will happily boot from that again after attempting to boot from r364030-OpenZFS2.

So now I have only 1 working BE and it feels a bit tricky to try an upgrade in place.
What's the best advice here?
I could switch back to base ZFS in this active BE, see if the system will be able to import zroot and mount all my datasets and boot, then try to create another BE using base ZFS and then attempt to update.

-- 
Marco van Lienen -- FreeBSD enthusiast
https://keybase.io/scarcry , GnuPG id: 8580E6CB
"The Tuck Pendleton machine...zero defects."