panic: lockmgr: locking against myself
Stopped in pid 416.1 (find) at  cpu_Debugger+0x4:       movl    %ebp,%esp
db> bt
cpu_Debugger(c679da84,0,0,c018e5c9,c679da18) at cpu_Debugger+0x4
panic(c020ca80,c67fd1ac,c6804a70,c0188c05,2) at panic+0xbd
lockmgr(c679da84,10002,c679da18,400,c415b00c) at lockmgr+0x6fd
genfs_lock(c6804ac4,0,0,c672c980,0) at genfs_lock+0x1d
vn_lock(c679da18,2,c6804b6c,0,c6804f04) at vn_lock+0x89
ufs_lookup(c6804be0,0,c6804bf0,c013487c,c6804f04) at ufs_lookup+0xc66
union_lookup1(c679da18,c6804c44,c6804c48,c6804f04,c6804f04) at
union_lookup1+0x8a
union_lookup(c6804d24,c6804d20,0,c672c980,c6881654) at union_lookup+0x136
lookup(c6804ee0,c6747400,400,c6804ef8,0) at lookup+0x308
namei(c6804ee0,20002,63d148a0,3e6b9fb8,0) at namei+0x35e
vn_open(c6804ee0,1,d24,c67fd1ac,c6804f78) at vn_open+0x1b7
sys_open(c672c980,c6804f80,c6804f78,c01d347f,0) at sys_open+0xd8
syscall_plain(1f,806001f,806001f,bfbf001f,ffffffff) at syscall_plain+0xa9

This seems to have to do with having an empty filesystem union-mounted over
/var.  I can trigger it fairly reliably with "find / -print".  Is this a Don't
Do That Then?

-s