Just winding up the great upgrade of "my" SPARC from 1.0 to -current,
and I get this.  Bleah.

Okay, I found out why less and ex were misbehaving (I don't think I
mentioned this on the list) - /dev/tty got replaced with a plain file.
So I finished the second-stage "make build", built a new kernel, and
rebooted (single-user).

Here's what happened.  (Braces { } surround commentary.)

# fsck /dev/rsd0[adeh]
{...fsck fixes up sd0a, zorching the old /sbin/init...btw, it also said
    the filesystem was already clean - IMO if the clean bits can't be
    trusted, they shouldn't be there...}
{...fsck starts on sd0d, and I L1-A before it gets very far...}
ok boot disk netbsd -s
{...comes up, apparently normally...}
init: copying out flags `-s' 3
init: copying out path `/sbin/init' 11
Enter pathname of shell or RETURN for sh:
# fsck /dev/rsd0[adeh]
{...all four filesystems fsck fine...}
# reboot
May 30 15:07:30 init: kernel security level changed from 0 to 1
syncing disks... fs = /
panic: update: rofs mod
Stopped at      0xf80d9f9c:     jmpl            [%o7 + 0x8], %g0
db> trace
{...uninteresting...everything here is repeated below...}
db> c
{...this traceback partially scrolled off the screen...}
  pc = f8025928  args = (100, f80ea400, 1, f962fc7c, f8571900, b) fp = f962fbc8
{f8025928 = _panic+0x54}
  pc = f8093c58  args = (100, f80ea400, 1, f8563000, f8571900, 9d) fp = f962fc30
{f8093c58 = _ffs_sync+0x44}
  pc = f80417d8  args = (0, 1, f855b880, f81054e8, f8093c14, f962ffb0) fp = f962fcb8
{f80417d8 = _dounmount+0x78}
  pc = f8040e48  args = (f8557200, 80000, f81054e8, f962fdd0, 0, 0) fp = f962fd20
{f8040e48 = _vfs_unmountall+0x38}
  pc = f8040f28  args = (0, 0, 0, f962e000, 0, fff) fp = f962fd88
{f8040f28 = _vfs_shutdown+0x58}
  pc = f80d13b4  args = (f8105400, f80e9c00, f80f4000, 0, f80fd400, a00) fp = f962fdf0
{f80d13b4 = _boot+0x48}
  pc = f8024550  args = (0, f85719fa, 0, 1, 0, 17) fp = f962fe58
{f8024550 = _reboot+0x20}
  pc = f80d8d34  args = (0, f962ff28, f962ff20, f8024530, 0, b) fp = f962fec0
{f80d8d34 = _syscall+0x1ec}
  pc = f8006710  args = (37, f962ffb0, 3068, 7484, 0, b) fp = f962ff50
{f8006710 = start+0x2710}
  pc = 2d0c  args = (0, ffffffff, 29a8, 203c, 84, f962ffb0) fp = f7fffc50

dumping to dev 701, offset 8
dump
sddump()        -- not implemented
error -1
rebooting

Unfortunately it does not appear to be repeatable, at least not in the
simplistic way of "boot disk netbsd -s" / "fsck /dev/rsd0[adeh]" /
"reboot", so I don't really know what can be said about it.

					der Mouse

			    mouse@collatz.mcrcim.mcgill.edu