> test -e ${root}/dev/zero || mount --bind /dev/ ${root}/dev > test -e ${root}/dev/shm/dh || mount --bind /dev/shm ${root}/dev/shm > test -e ${root}/dev/pts/0 || mount --bind /dev/pts/ ${root}/dev/pts
no need to separately mount shm and pts, just use --rbind, as the install doc recommends https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Base