=== UNPATCHED KERNEL (#0) — mount crafted image + read target.bin ===
(serial console / dfbsd-qemu/boot.log excerpt)

hammer2_mount: devstr="/dev/vn1@BOOT"
hammer2_mount: device="/dev/vn1" label="BOOT" rdonly=0
hammer2_ondisk: "/dev/vn1" zone=0 id=0 offset=0x0000000000000000 size=0x0000000010000000
hammer2_mount: "/dev/vn1": no recovery needed
hammer2_mount: hmp=0xfffff801193f8000 pmp=0xfffff80118980000
HAMMER2: VOLDATA DUMP
panic: hammer2_strategy_read_completion: unknown compression type
cpu tid = 3
Trace beginning at frame 0xfffff801178ff950
hammer2_xop_strategy_read() at hammer2_xop_strategy_read+0x606 0xffffffff809848d6
hammer2_xop_strategy_read() at hammer2_xop_strategy_read+0x606 0xffffffff809848d6
hammer2_primary_xops_thread() at hammer2_primary_xops_thread+0x280 0xffffffff8095da30
Debugger("panic")
CPU3 stopping CPUs: 0x00000037
 stopped
Stopped at      Debugger+0x7c:  movb    $0,0xbdaf09(%rip)
db>