Prevent auto reboot on system crash

[Ali Abdallah]

The problem is that, on crash the kernel drops crash messages on the tty0
console and reboots immediately, making it impossible to read them. (they
are not saved in /var/log/console.log for some reason).

According to
https://lists.freebsd.org/pipermail/freebsd-questions/2009-July/202210.html,
if debugging enabled in the kernel (KDB, DDB), setting
debug.debugger_on_panic: 1, should prevent the system from auto-reboot on
crash.

Apparently this is not working, at least for me. Also I've set
kern.panic_reboot_wait_time=-1, with no apparent effect.

One way to trigger system crash on 11.2 is to load the vboxdrv (installed
from pkg 'virtualbox-ose-kmod-5.2.8', not compiled from source). This will
crash the system reproducing the behavior described above.

Any help is highly appreciated.
Ali