serial console and panic

[manu%netbsd.org@localhost (Emmanuel Dreyfus)]

I have an amd64 machine that exhibit this since it has been upgraded to
5.0. It seems to happen in dhclient after a mysterious reboot (no log
about it) The machine is a NFS client for /usr, has a RAMdisk for /, and
a serial console

Any idea?

fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff804a2d25 cs 8 rflags 202 cr2
7f7ffd62f020 cpl 8 rsp ffff8000568626a8
db{0}> bt
breakpoint() at netbsd:breakpoint+0x5
comintr() at netbsd:comintr+0x53a
Xintr_ioapic_edge9() at netbsd:Xintr_ioapic_edge9+0xef
--- interrupt ---
lapic_gettick() at netbsd:lapic_gettick+0x7
re_miibus_readreg() at netbsd:re_miibus_readreg+0x18c
rgephy_load_dspcode() at netbsd:rgephy_load_dspcode+0xf2
rgephy_service() at netbsd:rgephy_service+0x32d
mii_down() at netbsd:mii_down+0x3b
re_stop() at netbsd:re_stop+0x2e
re_init() at netbsd:re_init+0x99
re_ioctl() at netbsd:re_ioctl+0x4d
ifioctl() at netbsd:ifioctl+0x635
soo_ioctl() at netbsd:soo_ioctl+0x24e
sys_ioctl() at netbsd:sys_ioctl+0x134
syscall() at netbsd:syscall+0xb6

-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu%netbsd.org@localhost