Normally when doing a chroot, you may have to mount some directories critical to Linux operation into the new root, like /proc and /sys. I'm not sure what you're running or the error you're getting, but I suspect either you may have to have the shared library available or mount it as mentioned.
# mount -o bind /proc /mnt/proc
# mount -o bind /sys /mnt/sys
# chroot /mnt
This makes the machines /proc and /sys directories available to the new root directory.