# The following assumes cwd is / and other OS is mounted on /mnt
# edit as necessary if, for example, other OS is mounted on /mnt/tmp
for i in dev dev/pts sys proc run; do sudo mount --bind /$i mnt/$i; done
# then run chroot /mnt/whatever /bin/bash
# Position at / also for cleanup:
for i in run proc sys dev/pts dev; do sudo umount mnt/$i; done