-current (cvs sources as of 12 hours ago) gave me this panic tonight on
NetBSD/mac68k while shutting down for a reboot.

May  2 00:13:40 unagi shutdown: reboot by devin:
syncing disks... done
NetBSD/mac68k does not trust itself to update the RTC on shutdown.
sd1(ncrcsci0:0:4:0): polling command not done
panic: scsipi_execute_xs
Stopped in pid 324 (reboot) at  _cpu_Debugger+0x6:      unlk    a6
db> t
_cpu_Debugger(...) + 6
_panic(...) + 60
_scsipi_execute_xs(...) + 20c
_scsi_scsipi_cmd(...) + de
_scsipi_command(...) + 6e
_sd_scsibus_flush(...) + 58
_sd_shutdown(...) + 24
_doshutdownhooks(...) + 78
_cpu_reboot(...) + 78
_sys_reboot(...) + 52
_syscall(d0) + 15e
_trap0() + e

Here's the dmesg:

[ using 217663 bytes of netbsd a.out symbol table ]
Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001
    The NetBSD Foundation, Inc.  All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
    The Regents of the University of California.  All rights reserved.

NetBSD 1.5U (UNAGI) #1: Tue May  1 19:29:45 JST 2001
    devin@unagi.pun-pun.prv:/usr/src/sys/arch/mac68k/compile/UNAGI
Apple Macintosh IIci  (68030)
cpu: delay factor 266
total memory = 65536 KB
avail memory = 89088 KB
using 844 buffers containing 3376 KB of memory
mrg: 'Mac IIci/Q700 ROMs' ROM glue, tracing off, debug off, silent traps
mrg: I/O map kludge for ROMs that use hardware addresses directly.
mainbus0 (root)
obio0 at mainbus0
adb0 at obio0
asc0 at obio0: Apple Sound Chip
intvid0 at obio0 @ 0: RBV video subsystem, Macintosh II display
intvid0: 640 x 480, monochrome
macfb0 at intvid0
wsdisplay0 at macfb0: console (std, vt100 emulation)
iwm0 at obio0: Apple GCR floppy disk controller
fd0 at iwm0 drive 0: (drive empty)
ncrscsi0 at obio0
scsibus0 at ncrscsi0 channel 0: 8 targets, 8 luns per target
zsc0 at obio0 chip type 0
zsc0 channel 0: d_speed   9600 DCD clk 0 CTS clk 0
zstty0 at zsc0 channel 0
zsc0 channel 1: d_speed   9600 DCD clk 0 CTS clk 0
zstty1 at zsc0 channel 1
nubus0 at mainbus0
ae0 at nubus0 slot c: MacCon Ethernet, 32KB memory
ae0: Ethernet address 00:00:94:07:ad:86
fpu0 at mainbus0 (mc68882)
adb0 (direct, II series): 2 targets
aed0 at adb0 addr 0: ADB Event device
akbd0 at adb0 addr 2: extended keyboard
wskbd0 at akbd0: console keyboard, using wsdisplay0
ams0 at adb0 addr 3: 1-button, 100 dpi mouse
wsmouse0 at ams0
scsibus0: waiting 2 seconds for devices to settle...
sd0 at scsibus0 target 1 lun 0: <SEAGATE, ST12400N SUN2.1G, 8562> SCSI2 0/direct fixed
sd0: 2048 MB, 2621 cyl, 19 head, 84 sec, 512 bytes/sect x 4194685 sectors
sd1 at scsibus0 target 4 lun 0: <COMPAQ, ST15150N, 5213> SCSI2 0/direct fixed
sd1: 4094 MB, 3712 cyl, 21 head, 107 sec, 512 bytes/sect x 8386000 sectors
boot device: sd1
root on sd1a dumps on sd1b
PRAM: 0x3aef5329, macos_boottime: 0x3aef531a.
root file system type: ffs


And the config file:

#	$NetBSD: GENERIC,v 1.106 2000/07/30 21:46:39 briggs Exp $
#
# GENERIC

include	"arch/mac68k/conf/std.mac68k"

#ident 		"GENERIC-$Revision: 1.106 $"

maxusers	16		# estimated number of users

# CPU support.  At least one is REQUIRED.
options 	M68030

# Standard system options

options 	UCONSOLE	# users can use TIOCCONS (for xconsole)
options 	INSECURE	# disable kernel security levels

options 	RTC_OFFSET=0	# hardware clock is this many mins. west of GMT
#options 	NTP		# NTP phase/frequency locked loop

options 	KTRACE		# system call tracing via ktrace(1)

options 	SYSVMSG		# System V-like message queues
options 	SYSVSEM		# System V-like semaphores
options 	SYSVSHM		# System V-like memory sharing
#options 	SHMMAXPGS=1024	# 1024 pages is the default

options 	LKM		# loadable kernel modules

# Diagnostic/debugging support options
options 	DIAGNOSTIC	# cheap kernel consistency checks
#options 	DEBUG		# expensive debugging checks/support
options 	KMEMSTATS	# kernel memory statistics (vmstat -m)
options 	DDB		# in-kernel debugger
options 	DDB_HISTORY_SIZE=100	# enable history editing in DDB
#options 	KGDB		# remote debugger
#options 	KGDBDEV=0xc01	# kgdb device number (dev_t)
#options 	KGDBRATE=38400	# baud rate
#makeoptions	DEBUG="-g"	# compile full symbol table

# Compatibility options
#options 	COMPAT_NOMID	# compatibility with 386BSD, BSDI, NetBSD 0.8,
#options 	COMPAT_09	# NetBSD 0.9,
options 	COMPAT_10	# NetBSD 1.0,
options 	COMPAT_11	# NetBSD 1.1,
options 	COMPAT_12	# NetBSD 1.2,
options 	COMPAT_13	# NetBSD 1.3,
options 	COMPAT_14	# NetBSD 1.4,
options 	COMPAT_43	# and 4.3BSD

options 	COMPAT_SUNOS	# compatibility with SunOS 4.x binaries
#options 	COMPAT_SVR4	# compatibility with SVR4 binaries
#options 	COMPAT_M68K4K	# compatibility with NetBSD/m68k4k binaries
#options 	COMPAT_LINUX	# compatibility with Linux/m68k binaries
#options 	EXEC_ELF32	# 32-bit ELF executables (Linux, SVR4)

# File systems
file-system 	FFS		# UFS
#file-system 	EXT2FS		# second extended file system (linux)
#file-system 	LFS		# log-structured file system
file-system 	MFS		# memory file system
file-system 	NFS		# Network File System client
file-system 	CD9660		# ISO 9660 + Rock Ridge file system
#file-system 	MSDOSFS		# MS-DOS file system
file-system 	FDESC		# /dev/fd
file-system 	KERNFS		# /kern
file-system 	NULLFS		# loopback file system
file-system 	OVERLAY		# overlay file system
file-system 	PORTAL		# portal filesystem (still experimental)
file-system 	PROCFS		# /proc
file-system 	UMAPFS		# NULLFS + uid and gid remapping
file-system 	UNION		# union file system
#file-system 	CODA		# Venus/Coda distributed file system

# File system options
options 	QUOTA		# UFS quotas
#options 	FFS_EI		# FFS Endian Independant support
options 	SOFTDEP		# FFS soft updates support.
options 	NFSSERVER	# Network File System server
#options 	EXT2FS_SYSTEM_FLAGS # makes ext2fs file flags (append and
				# immutable) behave as system flags.

# Networking options
options 	GATEWAY		# packet forwarding
options 	INET		# IP + ICMP + TCP + UDP
options 	INET6		# IPV6
#options 	IPSEC		# IP security
#options 	IPSEC_ESP	# IP security (encryption part; define w/IPSEC)
#options 	IPSEC_DEBUG	# debug for IP security
#options 	MROUTING	# IP multicast routing
#options 	NS		# XNS
#options 	NSIP		# XNS tunneling over IP
#options 	ISO,TPIP	# OSI
#options 	EON		# OSI tunneling over IP
#options 	CCITT,LLC,HDLC	# X.25
options 	NETATALK	# AppleTalk networking protocols
options 	PPP_BSDCOMP	# BSD-Compress compression support for PPP
options 	PPP_DEFLATE	# Deflate compression support for PPP
options 	PPP_FILTER	# Active filter support for PPP (requires bpf)
options 	PFIL_HOOKS	# pfil(9) packet filter hooks

# Compatibility with 4.2BSD implementation of TCP/IP.  Not recommended.
#options 	TCP_COMPAT_42

# These options enable verbose messages for several subsystems.
# Warning, these may compile large string tables into the kernel!
options 	SCSIVERBOSE	# human readable SCSI error messages

# wscons options
#options 	WSEMUL_SUN		# sun terminal emulation
options 	WSEMUL_VT100		# VT100 / VT220 emulation
options 	WSDISPLAY_COMPAT_ITEFONT # use ite font (6x10)

# rcons options; note that 1-bit and 8-bit displays are supported by default.
options 	RCONS_2BPP		# Support for 2-bit display
options 	RCONS_4BPP		# Support for 4-bit display
options 	RCONS_16BPP		# Support for 16-bit display

# Mac-specific options
#options 	ALTXBUTTONS	# Map Opt-{1,2,3} to mouse buttons
#options 	DISABLE_EXT_CACHE # If really paranoid, disable IIci ext. cache
options 	GRF_COMPAT	# Include grf compatibility code
#options 	MRG_ADB		# Use ROM-based ADB driver
options 	ZS_CONSOLE_ABORT

#options 	NFS_BOOT_DHCP

# Kernel root file system and dump configuration.
config		netbsd	root on ? type ?

#
# Device configuration
#

mainbus0 at root

fpu0 at mainbus?			# Floating-Point Coprocessor support


# Basic Bus Support

# On-board I/O bus support
obio0 at mainbus?

# NuBus support
nubus0 at mainbus?


# Console Devices

# Apple Desktop Bus interface
adb0	at obio?
aed*	at adb?				# ADB event device
akbd*	at adb?				# ADB keyboard
ams*	at adb?				# ADB mouse

# Basic frame buffer support
intvid0	at obio?			# Internal video hardware

# Device-independent frame buffer interface
macfb*	at intvid?

# Workstation Console devices
wsdisplay* at macfb? console ?
wskbd*	at akbd? console ?
wsmouse* at ams?


# Serial Devices

# On-board serial interface
zsc0	at obio?
zstty*	at zsc? channel ?


# SCSI Controllers and Devices

# SCSI controllers
# XXX - use only one of ncrscsi or sbc
ncrscsi0 at obio?			# SCSI NCR 5380
#sbc0	at obio? flags 0x1		# MI SCSI NCR 5380

# SCSI bus support
scsibus* at scsi?

# SCSI devices
sd*	at scsibus? target ? lun ?	# SCSI disk drives
st*	at scsibus? target ? lun ?	# SCSI tape drives
cd*	at scsibus? target ? lun ?	# SCSI CD-ROM drives
ch*	at scsibus? target ? lun ?	# SCSI autochangers
se*	at scsibus? target ? lun ?	# SCSI ethernet
ss*	at scsibus? target ? lun ?	# SCSI scanners
uk*	at scsibus? target ? lun ?	# SCSI unknown


# Miscellaneous mass storage devices

# IWM floppy disk controller
iwm0	at obio?			# Sony driver (800K GCR)
fd*	at iwm? drive ?


# Network Interfaces

# NuBus Ethernet controllers
ae*	at nubus?			# DP8390-based

# Audio Devices

# On-board audio hardware
asc0	at obio?			# ASC/EASC audio

# Pseudo-Devices

# disk/mass storage pseudo-devices
#pseudo-device	ccd		4	# concatenated/striped disk devices
#pseudo-device	raid		4	# RAIDframe disk driver
#options 	RAID_AUTOCONFIG		# auto-configuration of RAID components
pseudo-device	md		1	# memory disk device (ramdisk)
#pseudo-device	vcoda		1	# Venus/Coda distributed file system
pseudo-device	vnd		4	# disk-like interface to files

# network pseudo-devices
pseudo-device	bpfilter	12	# Berkeley packet filter
pseudo-device	ipfilter		# IP filter (firewall) and NAT
pseudo-device	loop			# network loopback
pseudo-device	ppp		2	# Point-to-Point Protocol
pseudo-device	sl		2	# Serial Line IP
#pseudo-device	strip		2	# Starmode Radio IP (Metricom)
pseudo-device	tun		2	# network tunneling over tty
#pseudo-device	gre		2	# generic L3 over IP tunnel
pseudo-device	gif		4	# IPv[46] over IPv[46] tunnel (RFC1933)
#pseudo-device	faith		1	# IPv[46] tcp relay translation i/f
#pseudo-device	stf		1	# 6to4 IPv6 over IPv4 encapsulation

# miscellaneous pseudo-devices
pseudo-device	grf		2	# grf emulation for wscons
pseudo-device	ite		1	# ite emulation for wscons
pseudo-device	pty		64	# pseudo-terminals
#pseudo-device	tb		1	# tablet line discipline

# random number generator pseudo-device
pseudo-device	rnd			# /dev/random and in-kernel generator
#options 	RND_COM			# use "com" randomness as well (BROKEN)