5.2.1-RC2: Fatal trap 12 when ACPI enabled

[Nate Lawson]

Please see the handbook section on acpi debugging.  In particular, you
should try disabling various subsystems to isolate the problem
(debug.acpi.disable, in the man page).  Also, a full dmesg is more
valuable than this snip.  Try unplugging the USB hard drive, etc.

Also, enable ddb in your kernel config and type "tr" when you get the
trap.

-Nate