[root@dfbsd ~]# /tmp/mirror_poc /mnt/f1 duptid
(ssh session died; guest dropped to ddb)
--- serial console (vm.sh log) ---
panic: assertion "elm->leaf.base.delete_tid != elm->leaf.base.create_tid" failed in hammer_delete_at_cursor at /usr/src/sys/vfs/hammer/hammer_object.c:2502
cpuid = 2
Trace beginning at frame 0xfffff8011803d118
hammer_delete_at_cursor() at hammer_delete_at_cursor+0x729 0xffffffff809443a9
hammer_ioc_mirror_write() at hammer_ioc_mirror_write+0x860 0xffffffff80940740
hammer_ioctl() at hammer_ioctl+0xebe 0xffffffff8093ecce
hammer_vop_ioctl() at hammer_vop_ioctl+0x48 0xffffffff80958978
vop_ioctl() at vop_ioctl+0x63 0xffffffff8070a793
Debugger("panic")
CPU2 stopping CPUs: 0x0000003b
 stopped
Stopped at      Debugger+0x7c:  movb    $0,0xbdaf09(%rip)
db>
(vm.sh status => down)