I wanted to try out the GNU usb install that was released with Guix 0.7. The problem is that when I try to boot from the USB, it freezes, with the word GRUB and a flashing type line. I followed the instructions. First I downloaded the compressed file from wget http://alpha.gnu.org/gnu/guix/gnu-usb-install-0.7.x86_64-linux.xz, then I extracted it xz gnu-usb-install-0.7.x86_64-linux.xz, then I dd it onto my 64GB USB flash drive, which I formatted to FAT32 and added the boot flag prior to dd'ing it, as so sudo dd if=gnu-usb-install-0.7.x86_64-linux of=/dev/sdb1. And as I said before, when I go on the boot menu and choose to boot from the flash drive, it just shows GRUB _, and everytime I press a key it beeps. 
GNU Guix usb-install freezes at GRUB after boot
grub;dd;gnu;freeze;fat32