Before chrooting, there are a few things that need to be done to set up the chroot environment. You will need to mount /proc, /sys and /dev inside your new system. Use the following commands to do so:

# cd /mnt/funtoo
# mount -t proc none proc
# mount --rbind /sys sys
# mount --rbind /dev dev

You'll also want to copy over resolv.conf in order to have proper resolution of Internet hostnames from inside the chroot:

# cp /etc/resolv.conf /mnt/funtoo/etc/

Now you can chroot into your new system. Use env before chroot to ensure that no environment settings from the installation media are pulled in to your new system: