Ok, my issue was that I was using the .img as if it was a .iso. Converting the .img to a .vdi as in https://www.debian.org/ports/hurd/hurd-install and now I can boot. I apologize for the confusion.
My issue now is that it crashes as soon as I select the boot option. And I'm getting this error: https://gist.github.com/osalbahr/1f0607121af92f80cbbc5099a1dd14f8?permalink_comment_id=5717389#gistcomment-5717389 ../i386/i386/apic.c:426: hpet_init: Assertion `hpet_addr !=0' failed.panic ../kern/debug.c:103: Debugger: Debugger invoked, but there isn't one! And then it reboots. I'm not sure why it's referencing i386 because I'm sure I used the amd64.img.
