It tries to mount zpool named
zroot and exits with error 19.
There is only ZFS on the HDD.
There is only swap line in
/etc/fstab (plus proc and linproc lines).
zroot in shown in
/boot/loader.conf
It shows a possibility like this:
zfs:tank
but panic occurs if enter
zfs:zroot
There is no
zroot among valid devices (shown after ?).
Panic also occurs if enter ada1p3, ada1p3a, /dev/ada1p3 ...
Sometimes it gets frozen, sometimes reboot is possible.
AHCI enabled long time ago and everything worked perfect for long time.
The problem appeared right after src updating and rebuilding world and kernel. World is still old since I cannot mount the pool.