I'm having the same problem but in an instance totally updated.
Some of the commands I have used.
root@sysresccd /mnt/funtoo % lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
loop0 7:0 0 469.9M 1 loop /livemnt/squashfs
sda 8:0 0 14.9G 0 disk
├─sda1 8:1 0 500M 0 part /mnt/funtoo/boot
├─sda2 8:2 0 4G 0 part [SWAP]
└─sda3 8:3 0 10.4G 0 part /mnt/funtoo
sdb 8:16 1 7.3G 0 disk
└─sdb1 8:17 1 7.3G 0 part /livemnt/boot
root@sysresccd /mnt/funtoo % uname -a
Linux sysresccd 4.14.32-std522-amd64 #2 SMP Sat Mar 31 20:05:28 UTC 2018 x86_64 Intel(R) Celeron(R) CPU 1007U @ 1.50GHz GenuineIntel GNU/Linux
root@sysresccd /mnt/funtoo % gcc -march=native -Q --help=target | grep march
-march= ivybridge
root@sysresccd /mnt/funtoo % tar xpf stage3-intel64-ivybridge-funtoo-current-2018-08-26.tar.xz
root@sysresccd /mnt/funtoo % cp /etc/resolv.conf /mnt/funtoo/etc/
root@sysresccd /mnt/funtoo % mount -t proc none proc
root@sysresccd /mnt/funtoo % mount --rbind /sys sys
root@sysresccd /mnt/funtoo % mount --rbind /dev dev
root@sysresccd /mnt/funtoo % env -i HOME=/root TERM=$TERM /bin/chroot . bash -l
zsh: illegal hardware instruction env -i HOME=/root TERM=$TERM /bin/chroot . bash -l
If anyone can help me. I will be many grateful.