FreeBSD 12.2-RC1 install media boot failure

I just tried to boot FreeBSD 12.1-RC1 in KVM/QEMU.  Specifically, I booted
FreeBSD-12.2-RC1-amd64-memstick.img as a virtual USB HDD.  The console was
flooded with error messages about "Device not configured"and errors from
the rc scripts, then it hanged.  Screenshot linked.  Any ideas?

http://bayimg.com/jaOnKAaga

-Alan