Updating to FreeBSD-current, can't mount -uw / : update: seemingly solved

I updated a FreeBSD-current to the newest FreeBSD-current/14, buildworld took 11:15 (hours:minutes), buildkernel was also successful, I even appeared to be successful with "dhclient re0".

UPDATING file says to boot single-user after buildkernel and installkernel, but then mount -u / or mount -uw / does not work as it did in previous times.

Results were

mount -uw / or mount -u / produces 
fstab: /etc/fstab:2: Inappropriate file type or format
fstab: /etc/fstab:2: Inappropriate file type or format

/etc/fstab
# Device	Mountpoint	FStype	Options	Dump	Pass#
/dev/gpt/Sea1-08  none swap 	0	0
/dev/gpt/Sea1-18  / ufs	rw	1	1
#/dev/gpt/Sea1-06 /home   ufs  rw 1  1

fsck -p produces

fstab: /etc/fstab:2: Inappropriate file type or format
/dev/gpt/Sea1-18: NO WRITE ACCESS
/dev/gpt/Sea1-18: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.

I tried fsck /dev/gpt/Sea1-18 and fsck / but did no better.

Now what do I do?  I also ran fsck_ffs instead of just fsck.

Do I need to boot NetBSD and run fsck_ffs or fsck_ffs -f from there?

Now I seem to have solved the problem.  Either rebooting or fixing /etc/fstab did it.

I may have had one too few fields on the /dev/gpt/Sea1-08 line, maybe that caused the system to misinterpret the next line.

I added sw between swap and 0, thus the corrected fstab is

# Device	Mountpoint	FStype	Options	Dump	Pass#
/dev/gpt/Sea1-08  none swap sw 	0	0
/dev/gpt/Sea1-18  / ufs	rw	1	1
#/dev/gpt/Sea1-06 /home   ufs  rw 1  1

Now I see from the emailing lists that etcupdate is replacing mergemaster, but UPDATING file still says to use mergemaster without mentioning etcupdate.

Developers, please update!

There are differences between NetBSD's etcupdate and FreeBSD's etcupdate.  I don't want to do the wrong thing in FreeBSD. 

Tom