(ssh stdout was lost when the panic killed the connection mid-run; the
serial console boot.log -- copied to panic.txt -- is the decisive record.
Host-side wrapper: 'dfbsd-qemu/vm.sh run_root /tmp/gif_race 240' started
at ~12:46:0x after 'sh /tmp/build.sh'; connection died during the 240s
race window; subsequent 'vm.sh status' => down.)