panic: vwakeup: neg numoutput, vp 0xcd1fff24

[Jukka Salmi <j+nbsd%2009.salmi.ch@localhost>]

Hello,

yesterday an i386 system running a 5.99.8 (almost) GENERIC kernel
paniced while building a release:

panic: vwakeup: neg numoutput, vp 0xcd1fff24
fatal breakpoint trap in supervisor mode
trap type 1 code 0 eip c0238154 cs 8 eflags 246 cr2 bb8f7000 ilevel 3
Stopped in pid 0.4 (system) at  netbsd:breakpoint+0x4:  popl    %ebp
db{0}> bt
breakpoint(c0990a55,cc1a3cfc,c09ae240,cbba9780,c0100ddf,cc1a3d00,3,6,3,c2972a80)
 at netbsd:breakpoint+0x4
panic(c099270e,cd1fff24,cc1a3d20,c068f6f8,c37a9248,0,0,3,c37a9248,c09ae240) at 
netbsd:panic+0x1ca
vwakeup(c37a9248,0,0,3,c37a9248,c09ae240,cc1a3d40,c068f76a,3,c068f7a3) at 
netbsd:vwakeup+0x45
biodone2(3,c068f7a3,8,282,cbb9e278,cbb9e004,cc1a3d80,c0492c7c,0,cbba9780) at 
netbsd:biodone2+0xc8
biointr(0,cbba9780,cbba9c80,cc1a3d80,0,0,0,0,3,0) at netbsd:biointr+0x3a
softint_dispatch(d77b8520,3,0,0,0,0,cc1a3d90,cc1a3b68,cc1a3bc0,28) at 
netbsd:softint_dispatch+0x7c
DDB lost frame for netbsd:Xsoftintr+0x3d, trying 0xcc1a3d88
Xsoftintr() at netbsd:Xsoftintr+0x3d
fatal page fault in supervisor mode
trap type 6 code 0 eip c02583e0 cs 8 eflags 10246 cr2 0 ilevel 8
kernel: supervisor trap page fault, code=0
Faulted in DDB; continuing...
db{0}> show registers
ds          0x10
es          0x10
fs          0x30
gs          0x10
edi         0xcbba9780
esi         0xc099270e  copyright+0x779ae
ebp         0xcc1a3cb0
ebx         0x104
edx         0x8
ecx         0x3
eax         0x1
eip         0xc0238154  breakpoint+0x4
cs          0x8
eflags      0x246
esp         0xcc1a3cb0
ss          0x10
netbsd:breakpoint+0x4:  popl    %ebp
db{0}> sync
syncing disks...

Any hints?

TIA, Jukka

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